Many technical indicators have been developed and new variants continue to be developed by traders with the aim of getting better results. New Indicators are often backtested on historic price and volume data to see how effective they would have been to predict future events.
^Murphy, John J. (1999). Technical analysis of the financial markets : a comprehensive guide to trading methods and applications (2nd ed. ed.). New York [u.a.]: New York Inst. of Finance. ISBN0735200661.CS1 maint: Extra text (link)