Alpha Bank is the fourth largest Greek bank by total assets but the second largest by market capitalisation as at December 2014. It has a subsidiary and branch in London, and branches and subsidiaries throughout Southeastern Europe (see "International expansion" below). Founded in 1879, it has been controlled by the Costopoulos family since the very beginning. Currently Ioannis Costopoulos, who is the grandson of the original founder John F. Costopoulos, and the nephew of Stavros Costopoulos, Foreign Minister in the liberal government of Georgios Papandreou, is the Chairman.
In 2000 "Banca Bucureşti" changed its name to "Alpha Bank Romania" (ABR). Monte dei Paschi di Siena took a 5% share of the bank. Alpha Bank’s share became 63%. ABR itself acquired a 12.5% stake in Victoria Bank (est. 1989), the largest private bank in Moldova.
In 2002 ACB acquired the minority stake and became the sole shareholder in Alpha Bank Skopje, accounting for 100% of its share capital.
In early 2005 Alpha Bank acquired 88.64% stake in Serbian Jubanka and changed its name to Alpha Bank Beograd.
Alpha Bank also has an extensive branch network in Bulgaria, the foundation of which it inherited from Ionian and Popular Bank, which entered in 1994 with a representative office in Sofia.
On November 24, 2006, Alpha Bank announced that an agreement had been reached with Anadolu Group to create a strong franchise in the Turkish financial sector. According to a press release, through this partnership, "Alpha Bank enters a rapidly developing sector in a large and fast growing market. The Anadolu Group is one of the preeminent industrial concerns in Turkey and is also the majority owner of Abank (Alternatifbank). The transaction is valued at USD 492.5 million (Euro 384.3 million). Alpha Bank will ultimately contribute a cash consideration equal to half of said amount. The two parties will jointly establish a fifty-fifty holding company whose assets consist of the shares currently owned by the Anadolu Group in both Abank and Alease (Alternatiflease), that is 94% and 95% stakes respectively. The holding company will also own, indirectly, 100% of the brokerage firm Alternatif Yatirim, 45% of the listed closed-end investment fund Alternatif Yatirim Ortkaligi, as well as the head offices of the bank and the brokerage company, situated in premium locations of Istanbul," the press release said.
On March 27, 2008, Alpha Bank reached a deal to buy a majority stake in newly established OJSC Astra Bank in the Ukraine as part of plans to expand in the region. Alpha Bank agreed to buy 90 percent of Astra Bank for 9 million euros.
In addition, Alpha Bank has a branch in London and a finance company, Alpha Finance US, in New York.