Prevailing bitcoin logo
|Ticker symbol||BTC, XBT[b]|
|Coins||Unspent outputs of transactions (in multiples of a satoshi):ch. 5|
|Original author(s)||Satoshi Nakamoto|
|White paper||"Bitcoin: A Peer-to-Peer Electronic Cash System"|
|Initial release||0.1.0 / 9 January 2009|
|Latest release||0.17.0 / 3 October 2018|
|Ledger start||3 January 2009|
|Timestamping scheme||Proof-of-work (partial hash inversion)|
|Issuance||Decentralized (block reward)|
|Block time||10 minutes|
|Circulating supply||₿16,858,762 (as of 11 February 2018[update])|
Bitcoin (₿) is a cryptocurrency, a form of electronic cash. It is a decentralized digital currency without a central bank or single administrator that can be sent from user-to-user on the peer-to-peer bitcoin network without the need for intermediaries.
Transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain. Bitcoin was invented by an unknown person or group of people using the name Satoshi Nakamoto and released as open-source software in 2009. Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies, products, and services. Research produced by the University of Cambridge estimates that in 2017, there were 2.9 to 5.8 million unique users using a cryptocurrency wallet, most of them using bitcoin.
Bitcoin has been criticized for its use in illegal transactions, its high electricity consumption, price volatility, thefts from exchanges, and the possibility that bitcoin is an economic bubble. Bitcoin has also been used as an investment, although several regulatory agencies have issued investor alerts about bitcoin.
- 1 History
- 2 Design
- 2.1 Blockchain
- 2.2 Transactions
- 2.3 Units
- 2.4 Transaction fees
- 2.5 Ownership
- 2.6 Mining
- 2.7 Supply
- 2.8 Wallets
- 2.9 Implementations
- 2.10 Decentralization and centralization
- 2.11 Privacy
- 2.12 Fungibility
- 2.13 Scalability
- 3 Ideology
- 4 Economics
- 5 Legal status, tax and regulation
- 6 Criticism
- 7 In popular culture
- 8 See also
- 9 Notes
- 10 References
- 11 External links
The domain name "bitcoin.org" was registered on 18 August 2008. In November 2008, a link to a paper authored by Satoshi Nakamoto titled Bitcoin: A Peer-to-Peer Electronic Cash System was posted to a cryptography mailing list. Nakamoto implemented the bitcoin software as open source code and released it in January 2009. Nakamoto's identity remains unknown.
In January 2009, the bitcoin network was created when Nakamoto mined the first block of the chain, known as the genesis block. Embedded in the coinbase of this block was the following text: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks." This note has been interpreted as both a timestamp and a comment on the instability caused by fractional-reserve banking.:18
The receiver of the first bitcoin transaction was cypherpunk Hal Finney, who created the first reusable proof-of-work system (RPOW) in 2004. Finney downloaded the bitcoin software on its release date, and on 12 January 2009 received ten bitcoins from Nakamoto. Other early cypherpunk supporters were creators of bitcoin predecessors: Wei Dai, creator of b-money, and Nick Szabo, creator of bit gold. In 2010, the first known commercial transaction using bitcoin occurred when programmer Laszlo Hanyecz bought two Papa John's pizzas for 10,000 bitcoin.
Nakamoto is estimated to have mined one million bitcoins before disappearing in 2010, when he handed the network alert key and control of the code repository over to Gavin Andresen. Andresen later became lead developer at the Bitcoin Foundation. Andresen then sought to decentralize control. This left opportunity for controversy to develop over the future development path of bitcoin.
After early "proof-of-concept" transactions, the first major users of bitcoin were black markets, such as Silk Road. During its 30 months of existence, beginning in February 2011, Silk Road exclusively accepted bitcoins as payment, transacting 9.9 million in bitcoins, worth about $214 million.:222
In 2011, the price started at $0.30 per bitcoin, growing to $5.27 for the year. The price rose to $31.50 on 8 June. Within a month the price fell to $11.00. The next month if fell to $7.80, and in another month to $4.77.
In 2012 bitcoin prices started at $5.27 growing to $13.30 for the year. By 9 January the price had risen to $7.38, but then crashed by 49% to $3.80 over the next 16 days. The price then rose to $16.41 on 17 August, but fell by 57% to $7.10 over the next three days.
The Bitcoin Foundation was founded in September 2012 to promote bitcoin's development and uptake.
In 2013 prices started at $13.30 rising to $770 by 1 January 2014.
In March 2013 the blockchain temporarily split into two independent chains with different rules. The two blockchains operated simultaneously for six hours, each with its own version of the transaction history. Normal operation was restored when the majority of the network downgraded to version 0.7 of the bitcoin software. The Mt. Gox exchange briefly halted bitcoin deposits and the price dropped by 23% to $37 before recovering to previous level of approximately $48 in the following hours. The US Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as bitcoin, classifying American bitcoin miners who sell their generated bitcoins as Money Service Businesses (MSBs), that are subject to registration or other legal obligations. In April, exchanges BitInstant and Mt. Gox experienced processing delays due to insufficient capacity resulting in the bitcoin price dropping from $266 to $76 before returning to $160 within six hours. The bitcoin price rose to $259 on 10 April, but then crashed by 83% to $45 over the next three days. On 15 May 2013, US authorities seized accounts associated with Mt. Gox after discovering it had not registered as a money transmitter with FinCEN in the US. On 23 June 2013, the US Drug Enforcement Administration (DEA) listed 11.02 bitcoins as a seized asset in a United States Department of Justice seizure notice pursuant to 21 U.S.C. § 881. This marked the first time a government agency had seized bitcoin. The FBI seized about 26,000 bitcoins in October 2013 from the dark web website Silk Road during the arrest of Ross William Ulbricht. Bitcoin's price rose to $755 on 19 November and crashed by 50% to $378 the same day. On 30 November 2013 the price reached $1,163 before starting a long-term crash, declining by 87% to $152 in January 2015. On 5 December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoins. After the announcement, the value of bitcoins dropped, and Baidu no longer accepted bitcoins for certain services. Buying real-world goods with any virtual currency had been illegal in China since at least 2009.
In 2014 prices started at $770 and fell to $314 for the year. In February 2014 the Mt. Gox exchange, the largest bitcoin exchange at the time, said that 850,000 bitcoins had been stolen from its customers, amounting to almost $500 million. Bitcoin's price fell by almost half, from $867 to $439 (a 49% drop). Prices remained low until late 2016.
In 2015 prices started at $314 and rose to $434 for the year. In 2016 prices rose to $998 on 1 January 2017.
China banned trading in bitcoin, with the first steps taken in September 2017, and a complete ban starting 1 February 2018. Bitcoin prices then fell from $9,052 to $6,914 on 5 February 2018. The percentage of bitcoin trading in renminbi fell from over 90% in September 2017 to less than 1% in June.
Bitcoin prices were negatively affected by several hacks or thefts from cryptocurrency exchanges, including thefts from Coincheck in January 2018, Coinrail and Bithumb in June, and Bancor in July. For the first six months of 2018, $761 million worth of cryptocurrencies was reported stolen from exchanges. Bitcoin's price was affected even though other cryptocurrencies were stolen at Coinrail and Bancor, as investors worried about the security of cryptocurrency exchanges.
The bitcoin blockchain is a public ledger that records bitcoin transactions. It is implemented as a chain of blocks, each block containing a hash of the previous block up to the genesis block[a] of the chain. A network of communicating nodes running bitcoin software maintains the blockchain.:215–219 Transactions of the form payer X sends Y bitcoins to payee Z are broadcast to this network using readily available software applications.
Network nodes can validate transactions, add them to their copy of the ledger, and then broadcast these ledger additions to other nodes. To achieve independent verification of the chain of ownership each network node stores its own copy of the blockchain. About every 10 minutes, a new group of accepted transactions, called a block, is created, added to the blockchain, and quickly published to all nodes, without requiring central oversight. This allows bitcoin software to determine when a particular bitcoin was spent, which is needed to prevent double-spending. A conventional ledger records the transfers of actual bills or promissory notes that exist apart from it, but the blockchain is the only place that bitcoins can be said to exist in the form of unspent outputs of transactions.:ch. 5
Transactions are defined using a Forth-like scripting language.:ch. 5 Transactions consist of one or more inputs and one or more outputs. When a user sends bitcoins, the user designates each address and the amount of bitcoin being sent to that address in an output. To prevent double spending, each input must refer to a previous unspent output in the blockchain. The use of multiple inputs corresponds to the use of multiple coins in a cash transaction. Since transactions can have multiple outputs, users can send bitcoins to multiple recipients in one transaction. As in a cash transaction, the sum of inputs (coins used to pay) can exceed the intended sum of payments. In such a case, an additional output is used, returning the change back to the payer. Any input satoshis not accounted for in the transaction outputs become the transaction fee.
The unit of account of the bitcoin system is a bitcoin. Ticker symbols used to represent bitcoin are BTC[b] and XBT.[c] Its Unicode character is ₿.:2 Small amounts of bitcoin used as alternative units are millibitcoin (mBTC), and satoshi (sat). Named in homage to bitcoin's creator, a satoshi is the smallest amount within bitcoin representing 0.00000001 bitcoins, one hundred millionth of a bitcoin. A millibitcoin equals 0.001 bitcoins, one thousandth of a bitcoin or 100,000 satoshis.
Though transaction fees are optional, miners can choose which transactions to process and prioritize those that pay higher fees. Miners may choose transactions based on the fee paid relative to their storage size, not the absolute amount of money paid as a fee. These fees are generally measured in satoshis per byte (sat/b). The size of transactions is dependent on the number of inputs used to create the transaction, and the number of outputs.:ch. 8
In the blockchain, bitcoins are registered to bitcoin addresses. Creating a bitcoin address requires nothing more than picking a random valid private key and computing the corresponding bitcoin address. This computation can be done in a split second. But the reverse, computing the private key of a given bitcoin address, is mathematically unfeasible. Users can tell others or make public a bitcoin address without compromising its corresponding private key. Moreover, the number of valid private keys is so vast that it is extremely unlikely someone will compute a key-pair that is already in use and has funds. The vast number of valid private keys makes it unfeasible that brute force could be used to compromise a private key. To be able to spend their bitcoins, the owner must know the corresponding private key and digitally sign the transaction. The network verifies the signature using the public key.:ch. 5
If the private key is lost, the bitcoin network will not recognize any other evidence of ownership; the coins are then unusable, and effectively lost. For example, in 2013 one user claimed to have lost 7,500 bitcoins, worth $7.5 million at the time, when he accidentally discarded a hard drive containing his private key. A backup of his key(s) would have prevented this.
About 20% of all bitcoins are believed to be lost. They would have a market value of about $20 billion at July 2018 prices. Approximately one million bitcoins, valued at $7 billion in July 2018, have been stolen.
Mining is a record-keeping service done through the use of computer processing power.[e] Miners keep the blockchain consistent, complete, and unalterable by repeatedly grouping newly broadcast transactions into a block, which is then broadcast to the network and verified by recipient nodes. Each block contains a SHA-256 cryptographic hash of the previous block, thus linking it to the previous block and giving the blockchain its name.:ch. 7
To be accepted by the rest of the network, a new block must contain a so-called proof-of-work (PoW). The system used is based on Adam Back's 1997 anti-spam scheme, Hashcash. The PoW requires miners to find a number called a nonce, such that when the block content is hashed along with the nonce, the result is numerically smaller than the network's difficulty target.:ch. 8 This proof is easy for any node in the network to verify, but extremely time-consuming to generate, as for a secure cryptographic hash, miners must try many different nonce values (usually the sequence of tested values is the ascending natural numbers: 0, 1, 2, 3, ...:ch. 8) before meeting the difficulty target.
Every 2,016 blocks (approximately 14 days at roughly 10 min per block), the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes. In this way the system automatically adapts to the total amount of mining power on the network.:ch. 8 Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.
The proof-of-work system, alongside the chaining of blocks, makes modifications of the blockchain extremely hard, as an attacker must modify all subsequent blocks in order for the modifications of one block to be accepted. As new blocks are mined all the time, the difficulty of modifying a block increases as time passes and the number of subsequent blocks (also called confirmations of the given block) increases.
Computing power is often bundled together or "pooled" to reduce variance in miner income. Individual mining rigs often have to wait for long periods to confirm a block of transactions and receive payment. In a pool, all participating miners get paid every time a participating server solves a block. This payment depends on the amount of work an individual miner contributed to help find that block.
The successful miner finding the new block is rewarded with newly created bitcoins and transaction fees. As of 9 July 2016[update], the reward amounted to 12.5 newly created bitcoins per block added to the blockchain. To claim the reward, a special transaction called a coinbase is included with the processed payments.:ch. 8 All bitcoins in existence have been created in such coinbase transactions. The bitcoin protocol specifies that the reward for adding a block will be halved every 210,000 blocks (approximately every four years). Eventually, the reward will decrease to zero, and the limit of 21 million bitcoins[f] will be reached c. 2140; the record keeping will then be rewarded solely by transaction fees.
In other words, bitcoin's inventor Nakamoto set a monetary policy based on artificial scarcity at bitcoin's inception that there would only ever be 21 million bitcoins in total. Their numbers are being released roughly every ten minutes and the rate at which they are generated would drop by half every four years until all were in circulation.
A wallet stores the information necessary to transact bitcoins. While wallets are often described as a place to hold or store bitcoins, due to the nature of the system, bitcoins are inseparable from the blockchain transaction ledger. A better way to describe a wallet is something that "stores the digital credentials for your bitcoin holdings" and allows one to access (and spend) them. Bitcoin uses public-key cryptography, in which two cryptographic keys, one public and one private, are generated. At its most basic, a wallet is a collection of these keys.
There are several modes which wallets can operate in. They have an inverse relationship with regards to trustlessness and computational requirements.
- Full clients verify transactions directly by downloading a full copy of the blockchain (over 150 GB As of January 2018[update]). They are the most secure and reliable way of using the network, as trust in external parties is not required. Full clients check the validity of mined blocks, preventing them from transacting on a chain that breaks or alters network rules. Because of its size and complexity, downloading and verifying the entire blockchain is not suitable for all computing devices.
- Lightweight clients consult full clients to send and receive transactions without requiring a local copy of the entire blockchain (see simplified payment verification – SPV). This makes lightweight clients much faster to set up and allows them to be used on low-power, low-bandwidth devices such as smartphones. When using a lightweight wallet, however, the user must trust the server to a certain degree, as it can report faulty values back to the user. Lightweight clients follow the longest blockchain and do not ensure it is valid, requiring trust in miners.
Third-party internet services called online wallets offer similar functionality but may be easier to use. In this case, credentials to access funds are stored with the online wallet provider rather than on the user's hardware. As a result, the user must have complete trust in the wallet provider. A malicious provider or a breach in server security may cause entrusted bitcoins to be stolen. An example of such a security breach occurred with Mt. Gox in 2011. This has led to the often-repeated meme "Not your keys, not your bitcoin".
Physical wallets store the credentials necessary to spend bitcoins offline. One notable example was a novelty coin with these credentials printed on the reverse side. Paper wallets are simply paper printouts.
Another type of wallet called a hardware wallet keeps credentials offline while facilitating transactions.
The first wallet program, simply named Bitcoin, and sometimes referred to as the Satoshi client, was released in 2009 by Satoshi Nakamoto as open-source code. In version 0.5 the client moved from the wxWidgets user interface toolkit to Qt, and the whole bundle was referred to as Bitcoin-Qt. After the release of version 0.9, the software bundle was renamed Bitcoin Core to distinguish itself from the underlying network.
On 1 August 2017, a hard fork of bitcoin was created, known as Bitcoin Cash. Bitcoin Cash has a larger block size limit and had an identical blockchain at the time of fork. On 24 October 2017 another hard fork, Bitcoin Gold, was created. Bitcoin Gold changes the proof-of-work algorithm used in mining, as the developers felt that mining had become too specialized.
Decentralization and centralization
Bitcoin does not have a central authority and the bitcoin network is decentralized:
- There is no central server, bitcoin network is peer-to-peer.
- There is no central storage, bitcoin ledger is distributed.
- The ledger is public, anybody can store it on their computer.:ch. 1
- There is no single administrator, the ledger is maintained by a network of equally privileged miners.:ch. 1
- Anybody can become a miner.:ch. 1
- The additions to the ledger are maintained through competition. Until a new block is added to the ledger, it is not known which miner will create the block.:ch. 1
- The issuance of bitcoins is decentralized. They are issued as a reward for the creation of a new block.
- Anybody can create a new bitcoin address (a bitcoin counterpart of a bank account) without needing any approval.:ch. 1
- Anybody can send a transaction to the network without needing any approval, the network merely confirms that the transaction is legitimate.:32
Trend towards centralization
Researchers have pointed out at a "trend towards centralization". Although bitcoin can be sent directly to the bitcoin network, in practice intermediaries are widely used.:220–222 Bitcoin miners join large mining pools to minimize the variance of their income.:215, 219–222:3 Because transactions on the network are confirmed by miners, decentralization of the network requires that no single miner or mining pool obtains 51% of the hashing power, which would allow them to double-spend coins, prevent certain transactions from being verified and prevent other miners from earning income. As of 2013 just six mining pools controlled 75% of overall bitcoin hashing power. In 2014 mining pool Ghash.io obtained 51% hashing power which raised significant controversies about the safety of the network. The pool has voluntarily capped their hashing power at 39.99% and requested other pools to act responsibly for the benefit of the whole network.
According to researchers, other parts of the ecosystem are also "controlled by a small set of entities", notably the maintenance of the official client software, online wallets and simplified payment verification (SPV) clients.
Bitcoin is pseudonymous, meaning that funds are not tied to real-world entities but rather bitcoin addresses. Owners of bitcoin addresses are not explicitly identified, but all transactions on the blockchain are public. In addition, transactions can be linked to individuals and companies through "idioms of use" (e.g., transactions that spend coins from multiple inputs indicate that the inputs may have a common owner) and corroborating public transaction data with known information on owners of certain addresses. Additionally, bitcoin exchanges, where bitcoins are traded for traditional currencies, may be required by law to collect personal information.
To heighten financial privacy, a new bitcoin address can be generated for each transaction. For example, hierarchical deterministic wallets generate pseudorandom "rolling addresses" for every transaction from a single seed, while only requiring a single passphrase to be remembered to recover all corresponding private keys. Researchers at Stanford and Concordia universities have also shown that bitcoin exchanges and other entities can prove assets, liabilities, and solvency without revealing their addresses using zero-knowledge proofs. "Bulletproofs," a version of Confidential Transactions proposed by Greg Maxwell, have been tested by Professor Dan Boneh of Stanford. Other solutions such Merkelized Abstract Syntax Trees (MAST), pay-to-script-hash (P2SH) with MERKLE-BRANCH-VERIFY, and "Tail Call Execution Semantics", have also been proposed to support private smart contracts.
Wallets and similar software technically handle all bitcoins as equivalent, establishing the basic level of fungibility. Researchers have pointed out that the history of each bitcoin is registered and publicly available in the blockchain ledger, and that some users may refuse to accept bitcoins coming from controversial transactions, which would harm bitcoin's fungibility.
The blocks in the blockchain were originally limited to 32 megabytes in size. The block size limit of one megabyte was introduced by Satoshi Nakamoto in 2010. Eventually the block size limit of one megabyte created problems for transaction processing, such as increasing transaction fees and delayed processing of transactions.
On 24 August 2017 (at block 481,824), Segregated Witness (SegWit) went live. Transactions contain some data which is only used to verify the transaction, and does not otherwise effect the movement of coins. SegWit introduced a new transaction format that moved this data into a new field in a backwards-compatible way. The segregated data, the so-called witness, is not sent to non-SegWit nodes and therefore does not form part of the blockchain as seen by legacy nodes. This lowers the size of the average transaction in such nodes' view, thereby increasing the block size without incurring the hard fork implied by other proposals for block size increases. Thus, per computer scientist Jochen Hoenicke, the actual block capacity depends on the ratio of SegWit transactions in the block, and on the ratio of signature data. Based on his estimate, if the ratio of SegWit transactions is 50%, the block capacity may be 1.25 megabytes. According to Hoenicke, if native SegWit addresses from Bitcoin Core version 0.16.0 are used, and SegWit adoption reaches 90% to 95%, a block size of up to 1.8 megabytes is possible.
Satoshi Nakamoto stated in his white paper that: "The root problem with conventional currencies is all the trust that’s required to make it work. The central bank must be trusted not to debase the currency, but the history of fiat currencies is full of breaches of that trust."
According to the European Central Bank, the decentralization of money offered by bitcoin has its theoretical roots in the Austrian school of economics, especially with Friedrich von Hayek in his book Denationalisation of Money: The Argument Refined, in which he advocates a complete free market in the production, distribution and management of money to end the monopoly of central banks.:22
Anarchist and libertarian theories
According to The New York Times, libertarians and anarchists were attracted to the idea. Early bitcoin supporter Roger Ver said: "At first, almost everyone who got involved did so for philosophical reasons. We saw bitcoin as a great idea, as a way to separate money from the state." The Economist describes bitcoin as "a techno-anarchist project to create an online version of cash, a way for people to transact without the possibility of interference from malicious governments or banks".
|The Declaration Of Bitcoin's Independence, BraveTheWorld, 4:38|
Nigel Dodd argues in The Social Life of Bitcoin that the essence of the bitcoin ideology is to remove money from social, as well as governmental, control. Dodd quotes a YouTube video, with Roger Ver, Jeff Berwick, Charlie Shrem, Andreas Antonopoulos, Gavin Wood, Trace Meyer and other proponents of bitcoin reading The Declaration of Bitcoin's Independence. The declaration includes a message of crypto-anarchism with the words: "Bitcoin is inherently anti-establishment, anti-system, and anti-state. Bitcoin undermines governments and disrupts institutions because bitcoin is fundamentally humanitarian."
David Golumbia says that the ideas influencing bitcoin advocates emerge from right-wing extremist movements such as the Liberty Lobby and the John Birch Society and their anti-Central Bank rhetoric, or, more recently, Ron Paul and Tea Party-style libertarianism. Steve Bannon, who owns a "good stake" in bitcoin, considers it to be "disruptive populism. It takes control back from central authorities. It's revolutionary."
However, researchers looking to uncover the reasons for interest in bitcoin did not find evidence in Google search data that this was linked to libertarianism.
Bitcoin is a digital asset designed to work in peer-to-peer transactions as a currency. Bitcoins have three qualities useful in a currency, according to The Economist in January 2015: they are "hard to earn, limited in supply and easy to verify". However, as of 2015[update] bitcoin functions more as a payment processor than as a currency.
Economists define money as a store of value, a medium of exchange, and a unit of account. According to The Economist in 2014, bitcoin functions best as a medium of exchange. However, this is debated, and a 2018 assessment by The Economist found that cryptocurrencies met none of these three criteria.
According to research by Cambridge University, between 2.9 million and 5.8 million unique users used a cryptocurrency wallet in 2017, most of them for bitcoin. The number of users has grown significantly since 2013, when there were 300,000 to 1.3 million users.
Acceptance by merchants
The overwhelming majority of bitcoin transactions take place on a cryptocurrency exchange, rather than being used in transactions with merchants. Delays processing payments through the blockchain of about ten minutes make bitcoin use very difficult in a retail setting. Prices are not usually quoted in units of bitcoin and many trades involve one, or sometimes two, conversions into conventional currencies. Merchants that do accept bitcoin payments may use payment service providers to perform the conversions.
In 2017 and 2018 bitcoin's acceptance among major online retailers included only three of the top 500 U.S. online merchants, down from five in 2016. Reasons for this decline include high transaction fees due to bitcoin's scalability issues and long transaction times.
Bloomberg reported that the largest 17 crypto merchant-processing services handled $69 million in June 2018, down from $411 million in September 2017. Bitcoin is "not actually usable" for retail transactions because of high costs and the inability to process chargebacks, according to Nicholas Weaver, a researcher quoted by Bloomberg. High price volatility and transaction fees make paying for small retail purchases with bitcoin impractical, according to economist Kim Grauer. However, bitcoin continues to be used for large-item purchases on sites such as Overstock.com, and for cross-border payments to freelancers and other vendors.
Bitcoins can be bought on digital currency exchanges.
Bitcoin has not gained acceptance for use in international remittances despite high fees charged by banks and Western Union who compete in this market. Unlike bitcoin, these competitors accept and dispense cash and do not require the use of the Internet which is a distinct advantage in lower income countries.
In 2014, the National Australia Bank closed accounts of businesses with ties to bitcoin, and HSBC refused to serve a hedge fund with links to bitcoin. Australian banks in general have been reported as closing down bank accounts of operators of businesses involving the currency.
As an investment
In 2013 and 2014, the European Banking Authority and the Financial Industry Regulatory Authority (FINRA), a United States self-regulatory organization, warned that investing in bitcoins carries significant risks. Forbes named bitcoin the best investment of 2013. In 2014, Bloomberg named bitcoin one of its worst investments of the year. In 2015, bitcoin topped Bloomberg's currency tables.
According to bitinfocharts.com, in 2017 there are 9,272 bitcoin wallets with more than $1 million worth of bitcoins. The exact number of bitcoin millionaires is uncertain as a single person can have more than one bitcoin wallet.
Venture capitalists, such as Peter Thiel's Founders Fund, which invested US$3 million in BitPay, do not purchase bitcoins themselves, but instead fund bitcoin infrastructure that provides payment systems to merchants, exchanges, wallet services, etc. In 2012, an incubator for bitcoin-focused start-ups was founded by Adam Draper, with financing help from his father, venture capitalist Tim Draper, one of the largest bitcoin holders after winning an auction of 30,000 bitcoins, at the time called "mystery buyer". The company's goal is to fund 100 bitcoin businesses within 2–3 years with $10,000 to $20,000 for a 6% stake. Investors also invest in bitcoin mining. According to a 2015 study by Paolo Tasca, bitcoin startups raised almost $1 billion in three years (Q1 2012 – Q1 2015).
Price and volatility
The price of bitcoins has gone through cycles of appreciation and depreciation referred to by some as bubbles and busts. In 2011, the value of one bitcoin rapidly rose from about US$0.30 to US$32 before returning to US$2. In the latter half of 2012 and during the 2012–13 Cypriot financial crisis, the bitcoin price began to rise, reaching a high of US$266 on 10 April 2013, before crashing to around US$50. On 29 November 2013, the cost of one bitcoin rose to a peak of US$1,242. In 2014, the price fell sharply, and as of April remained depressed at little more than half 2013 prices. As of August 2014[update] it was under US$600. During their time as bitcoin developers, Gavin Andresen and Mike Hearn warned that bubbles may occur.
Legal status, tax and regulation
Because of bitcoin's decentralized nature and its trading on online exchanges located in many countries, regulation of bitcoin has been difficult. However, the use of bitcoin can be criminalized, and shutting down exchanges and the peer-to-peer economy in a given country would constitute a de facto ban. The legal status of bitcoin varies substantially from country to country and is still undefined or changing in many of them. Regulations and bans that apply to bitcoin probably extend to similar cryptocurrency systems.
According to the Library of Congress, an "absolute ban" on trading or using cryptocurrencies applies in eight countries: Algeria, Bolivia, Egypt, Iraq, Morocco, Nepal, Pakistan, and the United Arab Emirates. An "implicit ban" applies in another 15 countries, which include Bahrain, Bangladesh, China, Colombia, the Dominican Republic, Indonesia, Iran, Kuwait, Lesotho, Lithuania, Macau, Oman, Qatar, Saudi Arabia and Taiwan.
If money services businesses, including cryptocurrency exchanges, money transmitters, and anonymizing services (known as "mixers" or "tumblers") do a substantial amount of business in the U.S., they are required to
- register with the U.S.FinCEN as a money services business
- design and enforce an anti-money laundering (AML) program, and
- keep appropriate records and make reports to FinCEN, including Suspicious Activity Reports (SARs) and Currency Transaction Reports (CTRs)
The U.S. Commodity Futures Trading Commission has issued four "Customer Advisories" for bitcoin and related investments. A July 2018 warning emphasized that trading in any cryptocurrency is often speculative, and there is a risk of theft from hacking, and fraud. A February 2018 advisory warned against investing an IRA fund into virtual currencies. A December 2017 advisory warned that virtual currencies are risky because:
- the exchanges are not regulated or supervised by a government agency
- the exchanges may lack system safeguards and customer protections
- large price swings and "flash crashes"
- market manipulation
- theft and hacking
- self-dealing by the exchanges
The U.S. Securities and Exchange Commission has also issued warnings. A May 2014 "Investor Alert" warned that investments involving bitcoin might have high rates of fraud, and that investors might be solicited on social media sites. An earlier "Investor Alert" warned about the use of bitcoin in Ponzi schemes.
The European Banking Authority issued a warning in 2013 focusing on the lack of regulation of bitcoin, the chance that exchanges would be hacked, the volatility of bitcoin's price, and general fraud.
The self-regulatory organization FINRA and the North American Securities Administrators Association have both issued investor alerts about bitcoin.
Price manipulation investigation
An official investigation into bitcoin traders was reported in May 2018. The U.S. Justice Department launched an investigation into possible price manipulation, including the techniques of spoofing and wash trades. Traders in the U.S., the U.K, South Korea, and possibly other countries are being investigated. Brett Redfearn, head of the U.S. Securities and Exchange Commission's Division of Trading and Markets, had identified several manipulation techniques of concern in March 2018.
The U.S. federal investigation was prompted by concerns of possible manipulation during futures settlement dates. The final settlement price of CME bitcoin futures is determined by prices on four exchanges, Bitstamp, Coinbase, itBit and Kraken. Following the first delivery date in January 2018, the CME requested extensive detailed trading information but several of the exchanges refused to provide it and later provided only limited data. The Commodity Futures Trading Commission then subpoenaed the data from the exchanges.
State and provincial securities regulators, coordinated through the North American Securities Administrators Association, are investigating "bitcoin scams" and ICOs in 40 jurisdictions.
Academic research published in the Journal of Monetary Economics concluded that price manipulation occurred during the Mt Gox bitcoin theft and that the market remains vulnerable to manipulation. The history of hacks, fraud and theft involving bitcoin dates back to at least 2011.
Research by John M. Griffin and Amin Shams in 2018 suggests that trading associated with increases in the amount of the Tether cryptocurrency and associated trading at the Bitfinex exchange account for about half of the price increase in bitcoin in late 2017.
J.L. van der Velde, CEO of both Bitfinex and Tether, denied the claims of price manipulation: "Bitfinex nor Tether is, or has ever, engaged in any sort of market or price manipulation. Tether issuances cannot be used to prop up the price of bitcoin or any other coin/token on Bitfinex."
|Cryptocurrencies: looking beyond the hype, Hyun Song Shin, Bank for International Settlements, 2:48|
The Bank for International Settlements summarized several criticisms of bitcoin in Chapter V of their 2018 annual report. The criticisms include the lack of stability in bitcoin's price, the high energy consumption, high and variable transactions costs, the poor security and fraud at cryptocurrency exchanges, vulnerability to debasement (from forking), and the influence of miners.
The Economist wrote in 2015 that these criticisms are unfair, predominantly because the shady image may compel users to overlook the capabilities of the blockchain technology, but also due to the fact that the volatility of bitcoin is changing in time.
Identification as a speculative bubble
Bitcoin and other cryptocurrencies have been identified as economic bubbles by at least eight Nobel Memorial Prize in Economic Sciences laureates, including Robert Shiller, Joseph Stiglitz, and Richard Thaler. Noted Keyensian economist Paul Krugman wrote in his New York Times column criticizing bitcoin, calling it a bubble and a fraud; and professor Nouriel Roubini of New York University called bitcoin the "mother of all bubbles." Central bankers, including former Federal Reserve Chairman Alan Greenspan, investors such as Warren Buffett, and George Soros have stated similar views, as have business executives such as Jamie Dimon and Jack Ma.
Tim Draper, a venture capitalist who has invested heavily in bitcoin, counters that bitcoin "is bigger than the Internet. It's bigger than the iron age, the Renaissance. It's bigger than the industrial revolution."
Bitcoin has been criticized for the amount of electricity consumed by mining. As of 2015, The Economist estimated that even if all miners used modern facilities, the combined electricity consumption would be 166.7 megawatts (1.46 terawatt-hours per year). At the end of 2017, the global bitcoin mining activity was estimated to consume between one and four gigawatts of electricity. Politico noted that the even high-end estimates of bitcoin's total consumption levels amount to only about 6% of the total power consumed by the global banking sector, and even if bitcoin's consumption levels increased 100 fold from today's levels, bitcoin's consumption would still only amount to about 2% of global power consumption.
To lower the costs, bitcoin miners have set up in places like Iceland where geothermal energy is cheap and cooling Arctic air is free. Bitcoin miners are known to use hydroelectric power in Tibet, Quebec, Washington (state), and Austria to reduce electricity costs. Miners are attracted to suppliers such as Hydro Quebec that have energy surpluses. According to a University of Cambridge study, much of bitcoin mining is done in China, where electricity is subsidized by the government.
Ponzi scheme and pyramid scheme concerns
Various journalists, economists, and the central bank of Estonia have voiced concerns that bitcoin is a Ponzi scheme. In 2013, Eric Posner, a law professor at the University of Chicago, stated that "a real Ponzi scheme takes fraud; bitcoin, by contrast, seems more like a collective delusion." A 2014 report by the World Bank concluded that bitcoin was not a deliberate Ponzi scheme.:7 The Swiss Federal Council:21 examined the concerns that bitcoin might be a pyramid scheme; it concluded that, "Since in the case of bitcoin the typical promises of profits are lacking, it cannot be assumed that bitcoin is a pyramid scheme." In July 2017, billionaire Howard Marks referred to bitcoin as a pyramid scheme.
Use in illegal transactions
The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and the media. In the United States, the FBI prepared an intelligence assessment, the SEC issued a pointed warning about investment schemes using virtual currencies, and the U.S. Senate held a hearing on virtual currencies in November 2013. The U.S. government claimed that bitcoin was used to facilitate payments related to Russian interference in the 2016 United States elections.
Several news outlets have asserted that the popularity of bitcoins hinges on the ability to use them to purchase illegal goods. Nobel-prize winning economist Joseph Stiglitz says that bitcoin's anonymity encourages money laundering and other crimes, "If you open up a hole like bitcoin, then all the nefarious activity will go through that hole, and no government can allow that." He's also said that if "you regulate it so you couldn’t engage in money laundering and all these other [crimes], there will be no demand for Bitcoin. By regulating the abuses, you are going to regulate it out of existence. It exists because of the abuses."
In 2014, researchers at the University of Kentucky found "robust evidence that computer programming enthusiasts and illegal activity drive interest in bitcoin, and find limited or no support for political and investment motives". Australian researchers have estimated that 25% of all bitcoin users and 44% of all bitcoin transactions are associated with illegal activity as of April 2017. There were an estimated 24 million bitcoin users primarily using bitcoin for illegal activity. They held $8 billion worth of bitcoin, and made 36 million transactions valued at $72 billion. A group of researches analyzed bitcoin transactions in 2016 and came to a conclusion that "some recent concerns regarding the use of bitcoin for illegal transactions at the present time might be overstated".
Bitcoin and other cryptocurrency advertisements are banned on Facebook, Google, Twitter, Bing, Snapchat, LinkedIn, and MailChimp. Chinese internet platforms Baidu, Tencent, and Weibo have also prohibited bitcoin advertisements. The Japanese platform Line and the Russian platform Yandex have similar prohibitions.
In popular culture
In Charles Stross' 2013 science fiction novel, Neptune's Brood, the universal interstellar payment system is known as "bitcoin" and operates using cryptography. Stross later blogged that the reference was intentional, saying "I wrote Neptune's Brood in 2011. Bitcoin was obscure back then, and I figured had just enough name recognition to be a useful term for an interstellar currency: it'd clue people in that it was a networked digital currency."
The 2014 documentary The Rise and Rise of Bitcoin portrays the diversity of motives behind the use of bitcoin by interviewing people who use it. These include a computer programmer and a drug dealer. The 2016 Netflix documentary Banking on Bitcoin is an introduction to bitcoin and the ideas behind cryptocurrency.
In September 2015, the establishment of the peer-reviewed academic journal Ledger (ISSN 2379-5980) was announced. It covers studies of cryptocurrencies and related technologies, and is published by the University of Pittsburgh. The journal encourages authors to digitally sign a file hash of submitted papers, which will then be timestamped into the bitcoin blockchain. Authors are also asked to include a personal bitcoin address in the first page of their papers.
- The genesis block is the block number 0. The timestamp of the block is 2009-01-03 18:15:05. This block is unlike all other blocks in that it does not have a previous block to reference.
- As of 2014[update], BTC is a commonly used code. It does not conform to ISO 4217 as BT is the country code of Bhutan, and ISO 4217 requires the first letter used in global commodities to be 'X'.
- As of 2014[update], XBT, a code that conforms to ISO 4217 though is not officially part of it, is used by Bloomberg L.P., CNNMoney, and xe.com.
- Relative mining difficulty is defined as the ratio of the difficulty target on 9 January 2009 to the current difficulty target.
- It is misleading to think that there is an analogy between gold mining and bitcoin mining. The fact is that gold miners are rewarded for producing gold, while bitcoin miners are not rewarded for producing bitcoins; they are rewarded for their record-keeping services.
- The exact number is 20,999,999.9769 bitcoins.:ch. 8
- The price of 1 bitcoin in US dollars.
- Volatility is calculated on a yearly basis.
- "Unicode 10.0.0". Unicode Consortium. 20 June 2017. Archived from the original on 20 June 2017. Retrieved 20 June 2017.
- Jason Mick (12 June 2011). "Cracking the Bitcoin: Digging Into a $131M USD Virtual Currency". Daily Tech. Archived from the original on 20 January 2013. Retrieved 30 September 2012.
- Andreas M. Antonopoulos (April 2014). Mastering Bitcoin: Unlocking Digital Crypto-Currencies. O'Reilly Media. ISBN 978-1-4493-7404-4.
- "Releases - bitcoin/bitcoin". Retrieved 9 October 2018 – via GitHub.
- Nakamoto, Satoshi (31 October 2008). "Bitcoin: A Peer-to-Peer Electronic Cash System" (PDF). bitcoin.org. Archived (PDF) from the original on 20 March 2014. Retrieved 28 April 2014.
- Nakamoto; et al. (1 April 2016). "Bitcoin source code - amount constraints". Archived from the original on 1 July 2018.
- "Statement of Jennifer Shasky Calvery, Director Financial Crimes Enforcement Network United States Department of the Treasury Before the United States Senate Committee on Banking, Housing, and Urban Affairs Subcommittee on National Security and International Trade and Finance Subcommittee on Economic Policy" (PDF). fincen.gov. Financial Crimes Enforcement Network. 19 November 2013. Archived (PDF) from the original on 9 October 2016. Retrieved 1 June 2014.
- Empson, Rip (28 March 2013). "Bitcoin: How an Unregulated, Decentralized Virtual Currency Just Became a Billion Dollar Market". TechCrunch. AOL inc. Archived from the original on 9 October 2016. Retrieved 8 October 2016.
- S., L. (2 November 2015). "Who is Satoshi Nakamoto?". The Economist. The Economist Newspaper Limited. Archived from the original on 21 August 2016. Retrieved 23 September 2016.
- Davis, Joshua (10 October 2011). "The Crypto-Currency: Bitcoin and its mysterious inventor". The New Yorker. Archived from the original on 1 November 2014. Retrieved 31 October 2014.
- "What is Bitcoin?". CNN Money. Archived from the original on 31 October 2015. Retrieved 16 November 2015.
- Hileman, Garrick; Rauchs, Michel. "Global Cryptocurrency Benchmarking Study" (PDF). Cambridge University. Archived (PDF) from the original on 10 April 2017. Retrieved 14 April 2017.
- Wolff-Mann, Ethan (27 April 2018). "'Only good for drug dealers': More Nobel prize winners snub bitcoin". Yahoo Finance. Archived from the original on 12 June 2018. Retrieved 7 June 2018.
- "Bitcoin". U.S. Commodity Futures Trading Commission. Archived from the original on 1 July 2018. Retrieved 17 July 2018.
- Bernard, Zoë (2 December 2017). "Everything you need to know about Bitcoin, its mysterious origins, and the many alleged identities of its creator". Business Insider. Archived from the original on 15 June 2018. Retrieved 15 June 2018.
- Nakamoto, Satoshi (3 January 2009). "Bitcoin". Archived from the original on 21 July 2017.
- Nakamoto, Satoshi (9 January 2009). "Bitcoin v0.1 released". Archived from the original on 26 March 2014.
- Wallace, Benjamin (23 November 2011). "The Rise and Fall of Bitcoin". Wired. Archived from the original on 31 October 2013. Retrieved 13 October 2012.
- "Block 0 – Bitcoin Block Explorer". Archived from the original on 15 October 2013.
- Pagliery, Jose (2014). Bitcoin: And the Future of Money. Triumph Books. ISBN 9781629370361. Archived from the original on 21 January 2018. Retrieved 20 January 2018.
- "Here's The Problem with the New Theory That A Japanese Math Professor Is The Inventor of Bitcoin". San Francisco Chronicle. Archived from the original on 4 January 2015. Retrieved 24 February 2015.
- Peterson, Andrea (3 January 2014). "Hal Finney received the first Bitcoin transaction. Here's how he describes it". The Washington Post. Archived from the original on 27 February 2015.
- Popper, Nathaniel (30 August 2014). "Hal Finney, Cryptographer and Bitcoin Pioneer, Dies at 58". NYTimes. Archived from the original on 3 September 2014. Retrieved 2 September 2014.
- Wallace, Benjamin (23 November 2011). "The Rise and Fall of Bitcoin". Wired. Archived from the original on 4 November 2013. Retrieved 4 November 2013.
- Kharpal, Arjun (2018-06-18). "Everything you need to know about the blockchain". CNBC. Retrieved 2018-09-13.
- McMillan, Robert. "Who Owns the World's Biggest Bitcoin Wallet? The FBI". Wired. Condé Nast. Archived from the original on 21 October 2016. Retrieved 7 October 2016.
- Simonite, Tom. "Meet Gavin Andresen, the most powerful person in the world of Bitcoin". MIT Technology Review. Retrieved 6 December 2017.
- Odell, Matt (21 September 2015). "A Solution To Bitcoin's Governance Problem". TechCrunch. Archived from the original on 26 January 2016. Retrieved 24 January 2016.
- Vigna, Paul (17 January 2016). "Is Bitcoin Breaking Up?". The Wall Street Journal. Archived from the original on 20 August 2016. Retrieved 8 November 2016.
- Rainer Böhme; Nicolas Christin; Benjamin Edelman; Tyler Moore (2015). "Bitcoin: Economics, Technology, and Governance". Journal of Economic Perspectives. Retrieved 21 July 2018.
- "Bitcoin Historical Prices". OfficialData.org. Archived from the original on 4 July 2018. Retrieved 3 July 2018.
- "Ex-Googler Gives the World a Better Bitcoin". WIRED. Archived from the original on 25 October 2017. Retrieved 25 October 2017.
- Yang, Stephanie (31 January 2018). "Want to Keep Up With Bitcoin Enthusiasts? Learn the Lingo". WSJ. Archived from the original on 12 June 2018. Retrieved 8 June 2018.
- French, Sally (9 February 2017). "Here's proof that this bitcoin crash is far from the worst the cryptocurrency has seen". Market Watch. Archived from the original on 3 July 2018. Retrieved 3 July 2018.
- Bustillos, Maria (1 April 2013). "The Bitcoin Boom". The New Yorker. Archived from the original on 2 July 2018. Retrieved 30 July 2018.
- Lee, Timothy (11 March 2013). "Major glitch in Bitcoin network sparks sell-off; price temporarily falls 23%". arstechnica.com. Archived from the original on 22 April 2013. Retrieved 15 February 2015.
- Lee, Timothy (12 March 2013). "Major glitch in Bitcoin network sparks sell-off; price temporarily falls 23%". Arstechnica. Archived from the original on 22 April 2013. Retrieved 12 March 2013.
- Blagdon, Jeff (12 March 2013). "Technical problems cause Bitcoin to plummet from record high, Mt. Gox suspends deposits". The Verge. Archived from the original on 22 April 2013. Retrieved 12 March 2013.
- "Bitcoin Charts". Archived from the original on 2014-05-09.
- Lee, Timothy (20 March 2013). "US regulator Bitcoin Exchanges Must Comply With Money Laundering Laws". Arstechnica. Archived from the original on 21 October 2013. Retrieved 28 July 2017.
Bitcoin miners must also register if they trade in their earnings for dollars.
- "US govt clarifies virtual currency regulatory position". Finextra. 19 March 2013. Archived from the original on 2014-03-26.
- "Application of FinCEN's Regulations to Persons Administering, Exchanging, or Using Virtual Currencies" (PDF). Department of the Treasury Financial Crimes Enforcement Network. Archived from the original (PDF) on 28 March 2013. Retrieved 19 March 2013.
- Roose, Kevin (8 April 2013) "Inside the Bitcoin Bubble: BitInstant's CEO – Daily Intelligencer". Archived from the original on 2014-04-09.. Nymag.com. Retrieved on 20 April 2013.
- "Bitcoin Exchange Rate". Bitcoinscharts.com. Archived from the original on 24 June 2012. Retrieved 15 August 2013.
- Dillet, Romain. "Feds Seize Assets From Mt. Gox's Dwolla Account, Accuse It Of Violating Money Transfer Regulations". Archived from the original on 9 October 2013. Retrieved 15 May 2013.
- Berson, Susan A. (2013). "Some basic rules for using 'bitcoin' as virtual money". American Bar Association. Archived from the original on 2013-10-29. Retrieved 2013-06-26.
- Cohen, Brian. "Users Bitcoins Seized by DEA". Archived from the original on 9 October 2013. Retrieved 14 October 2013.
- "The National Police completes the second phase of the operation "Ransomware"". El Cuerpo Nacional de Policía. Retrieved 2013-10-14.
- Sampson, Tim (2013). "U.S. government makes its first-ever Bitcoin seizure". The Daily Dot. Archived from the original on 30 June 2013. Retrieved 15 October 2013.
- "After Silk Road seizure, FBI Bitcoin wallet identified and pranked". Archived from the original on 2014-04-05.
- "Silkroad Seized Coins". Archived from the original on 9 January 2014. Retrieved 2 November 2013.
- Hill, Kashmir. "The FBI's Plan For The Millions Worth Of Bitcoins Seized From Silk Road". Forbes. Archived from the original on 2014-05-02.
- Kelion, Leo (18 December 2013). "Bitcoin sinks after China restricts yuan exchanges". bbc.com. BBC. Archived from the original on 19 December 2013. Retrieved 20 December 2013.
- "China bans banks from bitcoin transactions". The Sydney Morning Herald. Reuters. 6 December 2013. Archived from the original on 23 March 2014. Retrieved 31 October 2014.
- "Baidu Stops Accepting Bitcoins After China Ban". Bloomberg. New York. 7 December 2013. Archived from the original on 10 December 2013. Retrieved 11 December 2013.
- "China bars use of virtual money for trading in real goods". English.mofcom.gov.cn. 29 June 2009. Archived from the original on 29 November 2013. Retrieved 10 January 2014.
- "RMB Bitcoin trading falls below 1 pct of world total". Xinhuanet. Xinhua. 7 July 2018. Archived from the original on 10 July 2018. Retrieved 10 July 2018.
- "Bitcoin (USD) Price". Coindesk. Archived from the original on 4 July 2018. Retrieved 4 July 2018.
- Dawkins, David (10 July 2018). "Has CHINA burst the bitcoin BUBBLE? Trading in RMB drops from 90% to 1%". Express. Retrieved 10 July 2018.
- Chavez-Dreyfuss, Gertrude (3 July 2018). "Cryptocurrency exchange theft surges in first half of 2018: report". Reuters. Archived from the original on 4 July 2018. Retrieved 10 July 2018.
- "Cryptocurrencies Tumble After $32 Million South Korea Exchange Hack". Fortune. Bloomberg. 20 July 2018. Archived from the original on 11 July 2018. Retrieved 10 July 2018.
- Shane, Daniel (11 June 2018). "Billions in cryptocurrency wealth wiped out after hack". CNN. Archived from the original on 11 July 2018. Retrieved 10 July 2018.
- Russell, Jon (10 July 2018). "The crypto world's latest hack sees Israel's Bancor lose $23.5M". TechCrunch. Archived from the original on 10 July 2018. Retrieved 10 July 2018.
- "The great chain of being sure about things". The Economist. The Economist Newspaper Limited. 31 October 2015. Archived from the original on 3 July 2016. Retrieved 3 July 2016.
- Sparkes, Matthew (9 June 2014). "The coming digital anarchy". The Telegraph. London: Telegraph Media Group Limited. Archived from the original on 23 January 2015. Retrieved 7 January 2015.
- "Charts". Blockchain.info. Archived from the original on 3 November 2014. Retrieved 2 November 2014.
- Joshua A. Kroll; Ian C. Davey; Edward W. Felten (11–12 June 2013). "The Economics of Bitcoin Mining, or Bitcoin in the Presence of Adversaries" (PDF). The Twelfth Workshop on the Economics of Information Security (WEIS 2013). Archived (PDF) from the original on 9 May 2016. Retrieved 26 April 2016.
A transaction fee is like a tip or gratuity left for the miner.
- Nermin Hajdarbegovic (7 October 2014). "Bitcoin Foundation to Standardise Bitcoin Symbol and Code Next Year". CoinDesk. Archived from the original on 5 January 2015. Retrieved 28 January 2015.
- Romain Dillet (9 August 2013). "Bitcoin Ticker Available On Bloomberg Terminal For Employees". TechCrunch. Archived from the original on 1 November 2014. Retrieved 2 November 2014.
- "Bitcoin Composite Quote (XBT)". CNN Money. CNN. Archived from the original on 27 October 2014. Retrieved 2 November 2014.
- "XBT – Bitcoin". xe.com. Archived from the original on 2 November 2014. Retrieved 2 November 2014.
- "Regulation of Bitcoin in Selected Jurisdictions" (PDF). The Law Library of Congress, Global Legal Research Center. January 2014. Archived (PDF) from the original on 14 October 2014. Retrieved 26 August 2014.
- Katie Pisa & Natasha Maguder (9 July 2014). "Bitcoin your way to a double espresso". cnn.com. CNN. Archived from the original on 18 June 2015. Retrieved 23 April 2015.
- "Man Throws Away 7,500 Bitcoins, Now Worth $7.5 Million". CBS DC. 29 November 2013. Archived from the original on 15 January 2014. Retrieved 23 January 2014.
- Krause, Elliott (5 July 2018). "A Fifth of All Bitcoin Is Missing. These Crypto Hunters Can Help". Wall Street Journal. Archived from the original on 9 July 2018. Retrieved 8 July 2018.
- Detrixhe, John (6 July 2018). "The secret to crypto investing is there is no secret". Quartz. Archived from the original on 8 July 2018. Retrieved 8 July 2018.
- "List of cryptocurrency exchange hacks". Rados.io. Archived from the original on 9 July 2018. Retrieved 8 July 2018.
- Andolfatto, David (31 March 2014). "Bitcoin and Beyond: The Possibilities and Pitfalls of Virtual Currencies" (PDF). Dialogue with the Fed. Federal Reserve Bank of St. Louis. Archived (PDF) from the original on 9 April 2014. Retrieved 16 April 2014.
- Blocki, Jeremiah; Zhou, Hong-Sheng (1 January 2016). "Designing Proof of Human-Work Puzzles for Cryptocurrency and Beyond". Theory of Cryptography. Lecture Notes in Computer Science. Springer Berlin Heidelberg. 9986: 517–546. doi:10.1007/978-3-662-53644-5_20. ISBN 978-3-662-53643-8. Retrieved 4 February 2018.
- "Difficulty History" (The ratio of all hashes over valid hashes is D x 4,295,032,833, where D is the published "Difficulty" figure.). Blockchain.info. Archived from the original on 8 April 2015. Retrieved 26 March 2015.
- Hampton, Nikolai (5 September 2016). "Understanding the blockchain hype: Why much of it is nothing more than snake oil and spin". Computerworld. IDG. Archived from the original on 6 September 2016. Retrieved 5 September 2016.
- Biggs, John (8 April 2013). "How To Mine Bitcoins". Techcrunch. Archived from the original on 6 July 2017.
- Ashlee Vance (14 November 2013). "2014 Outlook: Bitcoin Mining Chips, a High-Tech Arms Race". Businessweek. Archived from the original on 21 November 2013. Retrieved 24 November 2013.
- "Block #420000". Blockchain.info. Archived from the original on 18 September 2016. Retrieved 11 September 2016.
- Ritchie S. King; Sam Williams; David Yanofsky (17 December 2013). "By reading this article, you're mining bitcoins". qz.com. Atlantic Media Co. Archived from the original on 17 December 2013. Retrieved 17 December 2013.
- Shin, Laura (24 May 2016). "Bitcoin Production Will Drop By Half In July, How Will That Affect The Price?". Forbes. Archived from the original on 24 May 2016. Retrieved 13 July 2016.
- Adam Serwer & Dana Liebelson (10 April 2013). "Bitcoin, Explained". motherjones.com. Mother Jones. Archived from the original on 27 April 2014. Retrieved 26 April 2014.
- Villasenor, John (26 April 2014). "Secure Bitcoin Storage: A Q&A With Three Bitcoin Company CEOs". forbes.com. Forbes. Archived from the original on 27 April 2014. Retrieved 26 April 2014.
- "Bitcoin: Bitcoin under pressure". The Economist. 30 November 2013. Archived from the original on 30 November 2013. Retrieved 30 November 2013.
- "Blockchain Size". Blockchain.info. Archived from the original on 27 May 2017. Retrieved 16 January 2018.
- Torpey, Kyle. "You Really Should Run a Bitcoin Full Node: Here's Why". Bitcoin Magazine. Archived from the original on 3 July 2017. Retrieved 29 November 2017.
- Gervais, Arthur; O. Karame, Ghassan; Gruber, Damian; Capkun, Srdjan. "On the Privacy Provisions of Bloom Filters in Lightweight Bitcoin Clients" (PDF). Archived (PDF) from the original on 5 October 2016. Retrieved 3 September 2016.
- Jon Matonis (26 April 2012). "Be Your Own Bank: Bitcoin Wallet for Apple". Forbes. Archived from the original on 12 October 2014. Retrieved 17 November 2014.
- Bill Barhydt (4 June 2014). "3 reasons Wall Street can't stay away from bitcoin". NBCUniversal. Archived from the original on 3 April 2015. Retrieved 2 April 2015.
- "MtGox gives bankruptcy details". bbc.com. BBC. 4 March 2014. Archived from the original on 12 March 2014. Retrieved 13 March 2014.
- "Antonopoulos: Your Keys, Your Bitcoin. Not Your Keys, Not Your Bitcoin". Cointelegraph. Archived from the original on 16 February 2018. Retrieved 16 February 2018.
- Staff, Verge (13 December 2013). "Casascius, maker of shiny physical bitcoins, shut down by Treasury Department". The Verge. Archived from the original on 10 January 2014. Retrieved 10 January 2014.
- Roberts, Daniel (15 December 2017). "How to send bitcoin to a hardware wallet". Yahoo Finance. Archived from the original on 17 February 2018. Retrieved 17 February 2018.
- Skudnov, Rostislav (2012). Bitcoin Clients (PDF) (Bachelor's Thesis). Turku University of Applied Sciences. Archived (PDF) from the original on 18 January 2014. Retrieved 16 January 2014.
- "Bitcoin Core version 0.9.0 released". bitcoin.org. Archived from the original on 27 February 2015. Retrieved 8 January 2015.
- Metz, Cade (19 August 2015). "The Bitcoin Schism Shows the Genius of Open Source". Wired. Condé Nast. Archived from the original on 30 June 2016. Retrieved 3 July 2016.
- Allison, Ian (28 April 2017). "Ethereum co-founder Dr Gavin Wood and company release Parity Bitcoin". International Business Times. Archived from the original on 28 April 2017. Retrieved 28 April 2017.
- Selena Larson (1 August 2017). "Bitcoin split in two, here's what that means". CNN Tech. Cable News Network. Archived from the original on 27 February 2018. Retrieved 2 April 2018.
- "Bitcoin Gold, the latest Bitcoin fork, explained". Ars Technica. Archived from the original on 29 December 2017. Retrieved 29 December 2017.
- Meola, Andrew (5 October 2017). "How distributed ledger technology will change the way the world works". Business Insider. Archived from the original on 27 April 2018. Retrieved 26 July 2018.
- Jerry Brito & Andrea Castillo (2013). "Bitcoin: A Primer for Policymakers" (PDF). Mercatus Center. George Mason University. Archived (PDF) from the original on 21 September 2013. Retrieved 22 October 2013.
- Tschorsch, Florian; Scheuermann, Björn (2016). "Bitcoin and Beyond: A Technical Survey on Decentralized Digital Currencies". IEEE Communications Surveys & Tutorials. 18 (3): 2084–2123. doi:10.1109/comst.2016.2535718. Archived from the original on 24 October 2017. Retrieved 24 October 2017.
- Beikverdi, A.; Song, J. (June 2015). "Trend of centralization in Bitcoin's distributed network". 2015 IEEE/ACIS 16th International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD): 1–6. doi:10.1109/SNPD.2015.7176229. ISBN 978-1-4799-8676-7. Archived from the original on 26 January 2018.
- Gervais, Arthur; Karame, Ghassan O.; Capkun, Vedran; Capkun, Srdjan. "Is Bitcoin a Decentralized Currency?". InfoQ. InfoQ & IEEE Computer Society. Archived from the original on 10 October 2016. Retrieved 11 October 2016.
- Wilhelm, Alex. "Popular Bitcoin Mining Pool Promises To Restrict Its Compute Power To Prevent Feared '51%' Fiasco". TechCrunch. Archived from the original on 5 December 2017. Retrieved 25 January 2018.
- Simonite, Tom (5 September 2013). "Mapping the Bitcoin Economy Could Reveal Users' Identities". MIT Technology Review. Retrieved 2 April 2014.
- Lee, Timothy (21 August 2013). "Five surprising facts about Bitcoin". The Washington Post. Archived from the original on 12 October 2013. Retrieved 2 April 2014.
- McMillan, Robert (6 June 2013). "How Bitcoin lets you spy on careless companies". wired.co.uk. Conde Nast. Archived from the original on 9 February 2014. Retrieved 2 April 2014.
- Potts, Jake (31 July 2015). "Mastering Bitcoin Privacy". Airbitz. Archived from the original on 10 August 2015. Retrieved 23 February 2016.
- Gaby G. Dagher; Benedikt Bünz; Joseph Bonneau; Jeremy Clark; Dan Boneh (26 October 2015). "Provisions: Privacy-preserving proofs of solvency for Bitcoin exchanges" (PDF). International Association for Cryptologic Research. Archived (PDF) from the original on 10 March 2016. Retrieved 23 February 2016.
- Michiel Mulders (20 December 2017). "How Bulletproofs Could Make Bitcoin Privacy Less Costly". bitcoin magazine. Archived from the original on 22 February 2018. Retrieved 22 February 2018.
- Ben-Sasson, Eli; Chiesa, Alessandro; Garman, Christina; Green, Matthew; Miers, Ian; Tromer, Eran; Virza, Madars (2014). "Zerocash: Decentralized Anonymous Payments from Bitcoin" (PDF). 2014 IEEE Symposium on Security and Privacy. IEEE computer society. Archived (PDF) from the original on 14 October 2014. Retrieved 31 October 2014.
- Orcutt, Mike (19 May 2015). "Leaderless Bitcoin Struggles to Make Its Most Crucial Decision". MIT Technology Review. Archived from the original on 18 October 2017. Retrieved 22 June 2017."Bitcoin Transaction Fees Are Pretty Low Right Now: Heres Why". 31 January 2018. Archived from the original on 15 May 2018. Retrieved 14 May 2018.
- Feuer, Alan (14 December 2013). "The Bitcoin Ideology". New York Times. Archived from the original on 1 July 2018. Retrieved 1 July 2018.
- Friedrich von Hayek (October 1976). Denationalisation of Money: The Argument Refined (PDF). 2 Lord North Street, Westminster, London SWIP 3LB: The institute of economic affairs. ISBN 0-255-36239-0. Archived (PDF) from the original on 4 March 2016. Retrieved 10 September 2015.
- European Central Bank (October 2012). Virtual Currency Schemes (PDF). Frankfurt am Main: European Central Bank. ISBN 978-92-899-0862-7. Archived (PDF) from the original on 2012-11-06.
- "Bitcoin and other cryptocurrencies are useless". The Economist. 30 August 2018. Retrieved 4 September 2018.
Lack of adoption and loads of volatility mean that cryptocurrencies satisfy none of those criteria. That does not mean they are going to go away (though scrutiny from regulators concerned about the fraud and sharp practice that is rife in the industry may dampen excitement in future). But as things stand there is little reason to think that cryptocurrencies will remain more than an overcomplicated, untrustworthy casino.
- Tourianski, Julia. "The Declaration Of Bitcoin's Independence". Archive.org. Retrieved 1 July 2018.
- Dodd, Nigel (2017). "The social life of Bitcoin" (PDF). LSE Research Online. Archived (PDF) from the original on 1 July 2018. Retrieved 1 July 2018.
- Golumbia, David (2015). Lovink, Geert, ed. Bitcoin as Politics: Distributed Right-Wing Extremism. Institute of Network Cultures, Amsterdam. pp. 117–131. ISBN 978-90-822345-5-8. Archived from the original on 5 June 2018. Retrieved 23 July 2018.
- Peters, Jeremy W.; Popper, Nathaniel (14 June 2018). "Stephen Bannon Buys Into Bitcoin". New York Times. Archived from the original on 1 July 2018. Retrieved 1 July 2018.
- Matthew Graham Wilson & Aaron Yelowitz (November 2014). "Characteristics of Bitcoin Users: An Analysis of Google Search Data". Social Science Research Network. Working Papers Series. SSRN 2518603.
- "Monetarists Anonymous". The Economist. The Economist Newspaper Limited. 29 September 2012. Archived from the original on 20 October 2013. Retrieved 21 October 2013.
- "The magic of mining". The Economist. 13 January 2015. Archived from the original on 12 January 2015. Retrieved 13 January 2015.
- Joyner, April (25 April 2014). "How bitcoin is moving money in Africa". usatoday.com. USA Today. Archived from the original on 1 May 2014. Retrieved 25 May 2014.
- "Free Exchange. Money from nothing. Chronic deflation may keep Bitcoin from displacing its rivals". The Economist. 15 March 2014. Archived from the original on 25 March 2014. Retrieved 25 March 2014.
- Osipovich, Alexander (2018-08-24). "It Was Meant to Be the Better Bitcoin. It's Down Nearly 90%". Wall Street Journal. ISSN 0099-9660. Retrieved 2018-09-12.
- Murphy, Hannah (8 June 2018). "Who really owns bitcoin now?". Financial Times. Archived from the original on 10 June 2018. Retrieved 10 June 2018.
- Karkaria, Urvaksh (23 September 2014). "Atlanta-based BitPay hooks up with PayPal to expand bitcoin adoption". Atlanta Business Chronicle. Archived from the original on 26 October 2014.
- Katz, Lily (12 July 2017). "Bitcoin Acceptance Among Retailers Is Low and Getting Lower". Bloomberg. Archived from the original on 25 January 2018. Retrieved 25 January 2018.
- Kharif, Olga (1 August 2018). "Bitcoin's Use in Commerce Keeps Falling Even as Volatility Eases". Bloomberg. Archived from the original on 2 August 2018. Retrieved 2 August 2018.
- "Bitcoin firms dumped by National Australia Bank as 'too risky'". Australian Associated Press. The Guardian. 10 April 2014. Archived from the original on 23 February 2015. Retrieved 23 February 2015.
- Weir, Mike (1 December 2014). "HSBC severs links with firm behind Bitcoin fund". bbc.com. BBC. Archived from the original on 3 February 2015. Retrieved 9 January 2015.
- "ACCC investigating why banks are closing bitcoin companies' accounts". Financial Review. Archived from the original on 11 February 2016. Retrieved 28 January 2016.
- "Bitcoin Shatters $7k Barrier After Futures Trading Announcement by CME Group". Archived from the original on 2 November 2017.
- "Archived copy". Archived from the original on 23 January 2018. Retrieved 16 December 2017.
- Lee, Timothy B. "The $11 million in bitcoins the Winklevoss brothers bought is now worth $32 million". The Switch. The Washington Post. Archived from the original on 6 July 2017. Retrieved 11 August 2017.
- "Jersey approve Bitcoin fund launch on island". BBC news. 10 July 2014. Archived from the original on 10 July 2014. Retrieved 10 July 2014.
- "Warning to consumers on virtual currencies" (PDF). European Banking Authority. 12 December 2013. Archived from the original (PDF) on 28 December 2013. Retrieved 23 December 2013.
- Jonathan Stempel (11 March 2014). "Beware Bitcoin: US brokerage regulator". reuters.com. Archived from the original on 15 March 2014. Retrieved 14 March 2014.
- Hill, Kashmir. "How You Should Have Spent $100 In 2013 (Hint: Bitcoin)". Forbes. Archived from the original on 19 February 2015. Retrieved 16 February 2015.
- Steverman, Ben (23 December 2014). "The Best and Worst Investments of 2014". bloomberg.com. Bloomberg LP. Archived from the original on 9 January 2015. Retrieved 9 January 2015.
- Gilbert, Mark (29 December 2015). "Bitcoin Won 2015. Apple ... Did Not". Bloomberg. Archived from the original on 29 December 2015. Retrieved 29 December 2015.
- "Top 100 Richest Bitcoin Addresses and Bitcoin distribution". bitinfocharts.com. Archived from the original on 15 October 2017. Retrieved 14 October 2017.
- Simonite, Tom (12 June 2013). "Bitcoin Millionaires Become Investing Angels". Computing News. MIT Technology Review. Retrieved 13 June 2013.
- Robin Sidel (1 December 2014). "Ten-hut! Bitcoin Recruits Snap To". Wall Street Journal. Dow Jones & Company. Archived from the original on 27 February 2015. Retrieved 9 December 2014.
- Alex Hern (1 July 2014). "Silk Road's legacy 30,000 bitcoin sold at auction to mystery buyers". The Guardian. Archived from the original on 23 October 2014. Retrieved 31 October 2014.
- "CoinSeed raises $7.5m, invests $5m in Bitcoin mining hardware – Investment Round Up". Red Herring. 24 January 2014. Archived from the original on 9 March 2014. Retrieved 9 March 2014.
- Tasca, Paolo (7 September 2015). "Digital Currencies: Principles, Trends, Opportunities, and Risks". Social Science Research Network. SSRN 2657598.
- Moore, Heidi (3 April 2013). "Confused about Bitcoin? It's 'the Harlem Shake of currency'". theguardian.com. The Guardian. Archived from the original on 1 March 2014. Retrieved 2 May 2014.
- Lee, Timothy (5 November 2013). "When will the people who called Bitcoin a bubble admit they were wrong". The Washington Post. Archived from the original on 11 January 2014. Retrieved 10 January 2014.
- Liu, Alec (19 March 2013). "When Governments Take Your Money, Bitcoin Looks Really Good". Motherboard. Archived from the original on 7 February 2014. Retrieved 7 January 2014.
- Lee, Timothy B. (11 April 2013). "An Illustrated History Of Bitcoin Crashes". Forbes. Archived from the original on 20 September 2015. Retrieved 7 January 2014.
- Ben Rooney (29 November 2013). "Bitcoin worth almost as much as gold". CNN. Archived from the original on 26 October 2014. Retrieved 31 October 2014.
- "Bitcoin prices remain below $600 amid bearish chart signals". nasdaq.com. August 2014. Archived from the original on 14 October 2014. Retrieved 31 October 2014.
- Dan Caplinger (4 April 2013). "Bitcoin's History of Crushing Speculators". The Motley Fool. Archived from the original on 7 January 2014. Retrieved 7 January 2014.
- Barford, Vanessa (13 December 2013). "Bitcoin: Price v hype". bbc.com. BBC. Archived from the original on 19 December 2013. Retrieved 23 December 2013.
- Williams, Mark T. (21 October 2014). "Virtual Currencies – Bitcoin Risk" (PDF). World Bank Conference Washington DC. Boston University. Archived (PDF) from the original on 11 November 2014. Retrieved 11 November 2014.
- "China May Be Gearing Up to Ban Bitcoin". pastemagazine.com. Archived from the original on 3 October 2017. Retrieved 6 October 2017.
The decentralized nature of bitcoin is such that it is impossible to “ban” the cryptocurrency, but if you shut down exchanges and the peer-to-peer economy running on bitcoin, it’s a de facto ban.
- Tasca, Paolo (7 September 2015). "Digital Currencies: Principles, Trends, Opportunities, and Risks". Social Science Research Network. SSRN 2657598.
- "Regulation of Cryptocurrency Around the World" (PDF). Library of Congress. The Law Library of Congress, Global Legal Research Center. June 2018. pp. 4–5. Retrieved 15 August 2018.
- "Prepared Remarks of FinCEN Director Kenneth A. Blanco, delivered at the 2018 Chicago-Kent Block (Legal) Tech Conference". FinCEN. U.S. Department of the Treasury. August 9, 2018. Retrieved 13 August 2018.
- "Customer Advisory: Use Caution When Buying Digital Coins or Tokens" (PDF). U.S.Commodity Futures Trading Commission. Archived (PDF) from the original on 17 July 2018. Retrieved 17 July 2018.
- "Customer Advisory: Beware "IRS Approved" Virtual Currency IRAs" (PDF). U.S Commodity Futures Trading Commission. Archived (PDF) from the original on 13 April 2018. Retrieved 17 July 2018.
- "Customer Advisory: Understand the Risks of Virtual Currency Trading". U.S. Commodity Futures Trading Commission. Missing or empty
- "Investor Alert: Bitcoin and Other Virtual Currency-related Investments". Investor.gov. U.S. Securities and Exchange Commission. 7 May 2014. Archived from the original on 30 June 2018. Retrieved 17 July 2018.
- "Ponzi schemes Using virtual Currencies" (PDF). sec.gov. U.S. Securities and Exchange Commission. Archived (PDF) from the original on 16 June 2018. Retrieved 17 July 2018.
- "Investor Alerts Don't Fall for Cryptocurrency-Related Stock Scams". FINRA.org. Financial Industry Regulatory Authority. 21 December 2017. Archived from the original on 1 July 2018. Retrieved 23 July 2018.
- "Informed Investor Advisory: Cryptocurrencies". North American Securities Administrators Association. April 2018. Archived from the original on 23 July 2018. Retrieved 23 July 2018.
- Dean, James (25 May 2018). "Bitcoin investigation to focus on British traders, US officials examine manipulation of cryptocurrency prices". The Times. Retrieved 25 May 2018.
- Cornish, Chloe (24 May 2018). "Bitcoin slips again on reports of US DoJ investigation". Financial Times. Archived from the original on 24 May 2018. Retrieved 24 May 2018.
- Robinson, Matt; Schoenberg, Tom (24 May 2018). "U.S. Launches Criminal Probe into Bitcoin Price Manipulation". Bloomberg. Archived from the original on 24 May 2018. Retrieved 24 May 2018.
- McCoy, Kevin (24 May 2018). "Bitcoin value gyrates amid report of Department of Justice manipulation investigation". USA Today. Archived from the original on 24 May 2018. Retrieved 25 May 2018.
- Rubin, Gabriel T.; Michaels, Dave; Osipovich, Alexander (8 June 2018). "U.S. regulators demand trading data from bitcoin exchanges in manipulation probe". MarketWatch. Archived from the original on 8 June 2018. Retrieved 9 June 2018. Note:this is a short open access version of a Wall Street Journal article
- Rubin, Gabriel T.; Michaels, Dave; Osipovich, Alexander (8 June 2018). "U.S. regulators demand trading data from bitcoin exchanges in manipulation probe". Wall Street Journal. Archived from the original on 8 June 2018. Retrieved 9 June 2018. (paywalled)
- Fung, Brian (21 May 2018). "State regulators unveil nationwide crackdown on suspicious cryptocurrency investment schemes". Washington Post. Archived from the original on 27 May 2018. Retrieved 27 May 2018.
- Gandal, Neil; Hamrick, J.T.; Moore, Tyler; Oberman, Tali (May 2018). "Price manipulation in the Bitcoin ecosystem". Journal of Monetary Economics. 95: 86–96. Retrieved 25 May 2018.
- Lee, Tim (12 December 2017). "A brief history of Bitcoin hacks and frauds". Ars Technica. Archived from the original on 28 May 2018. Retrieved 27 May 2018.
- Griffin, John M.; Shams, Amin (13 June 2018). "Is Bitcoin Really Un-Tethered?". Social Sciences Research Network. Archived from the original on 13 June 2018. Retrieved 13 June 2018.
- Popper, Nathaniel (13 June 2018). "Bitcoin's Price Was Artificially Inflated Last Year, Researchers Say". New York Times. Archived from the original on 13 June 2018. Retrieved 13 June 2018.
- Shaban, Hamza (14 June 2018). "Bitcoin's astronomical rise last year was buoyed by market manipulation, researchers say". Washington Post. Archived from the original on 15 June 2018. Retrieved 14 June 2018.
- Janda, Michael (18 June 2018). "Cryptocurrencies like bitcoin cannot replace money, says Bank for International Settlements". ABC (Australia). Archived from the original on 18 June 2018. Retrieved 18 June 2018.
- Hyun Song Shin (June 2018). "Chapter V. Cryptocurrencies: looking beyond the hype" (PDF). BIS 2018 Annual Economic Report. Bank for International Settlements. Archived (PDF) from the original on 18 June 2018. Retrieved 19 June 2018.
Put in the simplest terms, the quest for decentralised trust has quickly become an environmental disaster.
- Hiltzik, Michael (18 June 2018). "Is this scathing report the death knell for bitcoin?". Los Angeles Times. Archived from the original on 18 June 2018. Retrieved 19 June 2018.
- "The trust machine". The Economist. 31 October 2015. Retrieved 1 August 2018.
- Shiller, Robert (1 March 2014). "In Search of a Stable Electronic Currency". New York Times. Archived from the original on 24 October 2014. Retrieved 31 October 2014.
- Costelloe, Kevin (29 November 2017). "Bitcoin 'Ought to Be Outlawed,' Nobel Prize Winner Stiglitz Says". Bloomberg. Archived from the original on 12 June 2018. Retrieved 5 June 2018.
It doesn’t serve any socially useful function.
- "Economics Nobel prize winner, Richard Thaler: "The market that looks most like a bubble to me is Bitcoin and its brethren"". ECO Portuguese Economy. 22 January 2018. Archived from the original on 12 June 2018. Retrieved 7 June 2018.
- Krugman, Paul (29 January 2018). "Bubble, Bubble, Fraud and Trouble". New York Times. Archived from the original on 4 June 2018. Retrieved 7 June 2018.
- "Bitcoin biggest bubble in history, says economist who predicted 2008 crash". Archived from the original on 12 June 2018.
- Kearns, Jeff (4 December 2013). "Greenspan Says Bitcoin a Bubble Without Intrinsic Currency Value". bloomberg.com. Bloomberg LP. Archived from the original on 29 December 2013. Retrieved 23 December 2013.
- Crippen, Alex (14 March 2014). "Bitcoin? Here's what Warren Buffett is saying". CNBC. Archived from the original on 13 January 2017. Retrieved 11 January 2017.
- Cheng, Evelyn (7 June 2018). "Warren Buffett and Jamie Dimon on bitcoin: Beware". CNBC. Archived from the original on 9 June 2018. Retrieved 7 June 2018.
- Porzecanski, Katia (25 January 2018). "George Soros: Bitcoin is a bubble, Trump is a 'danger to the world'". Globe and Mail. Bloomberg News. Archived from the original on 9 June 2018. Retrieved 7 June 2018.
- Yang, Yingzhi (18 May 2018). "There's a bitcoin bubble, says Alibaba executive chairman Jack Ma". South China Morning Post. Archived from the original on 10 June 2018. Retrieved 10 June 2018.
- "Bitcoin is more than a bubble and is here to stay". Intelligence Squared. Archived from the original on 28 April 2018. Retrieved 17 July 2018. See transcript or at 6:00 of the video
- Mooney, Chris; Mufson, Steven (19 December 2017). "Why the bitcoin craze is using up so much energy". The Washington Post. Archived from the original on 9 January 2018. Retrieved 11 January 2018.
several experts told The Washington Post that bitcoin probably uses as much as 1 to 4 gigawatts, or billion watts, of electricity, roughly the output of one to three nuclear reactors.
- Roberts, Paul (9 March 2018). "This Is What Happens When Bitcoin Miners Take Over Your Town - Eastern Washington had cheap power and tons of space. Then the suitcases of cash started arriving". Politico. Archived from the original on 9 March 2018. Retrieved 16 March 2018.
- O'Brien, Matt (13 June 2015). "The scam called Bitcoin". Daily Herald. Archived from the original on 16 June 2015. Retrieved 20 September 2016.
- Maras, Elliot (14 September 2016). "China's Mining Dominance: Good Or Bad For Bitcoin?". Cryptocoin News. Archived from the original on 26 November 2016. Retrieved 25 November 2016.
- "Montreal entrepreneur banking on province's largest bitcoin 'mining' operation". Cryptocoin News. 15 November 2017. Archived from the original on 10 January 2018. Retrieved 7 January 2018.
- Potenza, Alessandra (21 December 2017). "Can renewable power offset bitcoin's massive energy demands?". TheVerge News. Archived from the original on 12 January 2018. Retrieved 12 January 2018.
- Lampert, Allison (12 January 2018). "Chinese bitcoin miners eye sites in energy-rich Canada". Reuters. Archived from the original on 14 January 2018. Retrieved 14 January 2018.
- "Bitcoin is literally ruining the earth, claim experts". The Independent. 6 December 2017. Archived from the original on 19 January 2018. Retrieved 23 January 2018.
- "The Hard Math Behind Bitcoin's Global Warming Problem". WIRED. 15 December 2017. Archived from the original on 21 January 2018. Retrieved 23 January 2018.
- Braue, David (11 March 2014). "Bitcoin confidence game is a Ponzi scheme for the 21st century". ZDNet. Archived from the original on 6 October 2016. Retrieved 5 October 2016.
- Clinch, Matt (10 March 2014). "Roubini launches stinging attack on bitcoin". CNBC. Archived from the original on 6 October 2014. Retrieved 2 July 2014.
- North, Gary (3 December 2013). "Bitcoins: The second biggest Ponzi scheme in history". The Daily Dot. Archived from the original on 17 June 2016. Retrieved 23 May 2016.
- Ott Ummelas & Milda Seputyte (31 January 2014). "Bitcoin 'Ponzi' Concern Sparks Warning From Estonia Bank". bloomberg.com. Bloomberg. Archived from the original on 29 March 2014. Retrieved 1 April 2014.
- Posner, Eric (11 April 2013). "Bitcoin is a Ponzi scheme—the Internet's favorite currency will collapse". Slate. Archived from the original on 26 March 2014. Retrieved 1 April 2014.
- Kaushik Basu (July 2014). "Ponzis: The Science and Mystique of a Class of Financial Frauds" (PDF). World Bank Group. Archived (PDF) from the original on 31 October 2014. Retrieved 30 October 2014.
- "Federal Council report on virtual currencies in response to the Schwaab (13.3687) and Weibel (13.4070) postulates" (PDF). Federal Council (Switzerland). Swiss Confederation. 25 June 2014. Archived (PDF) from the original on 5 December 2014. Retrieved 28 November 2014.
- "This Billionaire Just Called Bitcoin a 'Pyramid Scheme'". Archived from the original on 24 September 2017. Retrieved 23 September 2017.
- Harney, Alexandra; Stecklow, Steve (2017-11-16). "Twice burned - How Mt. Gox's bitcoin customers could lose again". Reuters. Retrieved 2018-09-06.
- Lavin, Tim (8 August 2013). "The SEC Shows Why Bitcoin Is Doomed". bloomberg.com. Bloomberg LP. Archived from the original on 25 March 2014. Retrieved 20 October 2013.
- "Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity" (PDF). Cyber Intelligence Section and Criminal Intelligence Section. FBI. 24 April 2012. Archived (PDF) from the original on 14 October 2014. Retrieved 2 November 2014.
- Lee, Timothy B. (21 November 2013). "Here's how Bitcoin charmed Washington". The Washington Post. Archived from the original on 1 January 2017. Retrieved 10 October 2016.
- Popper, Nathaniel (13 July 2018). "How Russian Spies Hid Behind Bitcoin in Hacking Campaign". NYT. Archived from the original on 14 July 2018. Retrieved 14 July 2018.
- Ball, James (22 March 2013). "Silk Road: the online drug marketplace that officials seem powerless to stop". theguardian.com. Guardian News and Media Limited. Archived from the original on 12 October 2013. Retrieved 20 October 2013.
- Montag, Ali (9 July 2018). "Nobel-winning economist: Authorities will bring down 'hammer' on bitcoin". CNBC. Archived from the original on 11 July 2018. Retrieved 11 July 2018.
- Newlands, Chris (9 July 2018). "Stiglitz, Roubini and Rogoff lead joint attack on bitcoin". Financial News. Archived from the original on 11 July 2018. Retrieved 11 July 2018.
- Foley, Sean; Karlsen, Jonathan R.; Putniņš, Tālis J. (19 February 2018). "Sex, drugs, and bitcoin: How much illegal activity is financed through cryptocurrencies?". University of Oxford Faculty of Law. Oxford Business Law Blog. Archived from the original on 10 June 2018. Retrieved 11 June 2018.
- Foley, Sean; Karlsen, Jonathan R.; Putniņš, Tālis J. (30 January 2018). "Sex, Drugs, and Bitcoin: How Much Illegal Activity Is Financed Through Cryptocurrencies?". Social Science Research Network. Archived from the original on 12 July 2018. Retrieved 11 June 2018.
- "The Evolution of the Bitcoin Economy and Analyzing the Network of Payment Relationships". 9 August 2017. Archived from the original on 12 July 2018. Retrieved 11 July 2018.
- Matsakis, Louise (30 January 2018). "Cryptocurrency scams are just straight-up trolling at this point". Wired. Archived from the original on 1 April 2018. Retrieved 2 April 2018.
- Weinglass, Simona (28 March 2018). "European Union bans binary options, strictly regulates CFDs". Times of Israel. Archived from the original on 1 April 2018. Retrieved 2 April 2018.
- Alsoszatai-Petheo, Melissa (14 May 2018). "Bing Ads to disallow cryptocurrency advertising". Microsoft. Archived from the original on 17 May 2018. Retrieved 16 May 2018.
- French, Jordan (2 April 2018). "3 Key Factors Behind Bitcoin's Current Slide". theStreet.com. Archived from the original on 3 April 2018. Retrieved 2 April 2018.
- Wilson, Thomas (28 March 2018). "Twitter and LinkedIn ban cryptocurrency adverts – leaving regulators behind". Independent. Reuters. Archived from the original on 4 April 2018. Retrieved 3 April 2018.
- Stross, Charles (2013). Neptune's Brood (First ed.). New York: Penguin Group USA. ISBN 978-0-425-25677-0.
It’s theft-proof too – for each bitcoin is cryptographically signed by the mind of its owner.
- "Crib Sheet: Neptune's Brood – Charlie's Diary". www.antipope.org. Archived from the original on 14 June 2017. Retrieved 5 December 2017.
I wrote Neptune's Brood in 2011. Bitcoin was obscure back then, and I figured had just enough name recognition to be a useful term for an interstellar currency: it'd clue people in that it was a networked digital currency.
- Kenigsberg, Ben (2 October 2014). "Financial Wild West". The New York Times. Archived from the original on 18 May 2015. Retrieved 8 May 2015.
- Michel, Lincoln (16 December 2017). "What the Hell Is Bitcoin? Let This Documentary on Netflix Explain". GQ. Retrieved 10 October 2018.
- "Introducing Ledger, the First Bitcoin-Only Academic Journal". Motherboard. Archived from the original on 10 January 2017.
- "Editorial Policies". ledgerjournal.org. Archived from the original on 23 December 2016.
- "How to Write and Format an Article for Ledger" (PDF). Ledger. 2015. doi:10.5195/LEDGER.2015.1 (inactive 18 March 2018). Archived (PDF) from the original on 22 September 2015.
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