But, Then Why Do They Spend Money On It?

Does intraday technical analysis in the U.S. equity market have value?

Ben Marshall, Rochester Cahan & Jared Cahan
Journal of Empirical Finance, March 2008, Pages 199-210

Abstract:
This paper investigates whether intraday technical analysis is profitable in
the U.S. equity market. Surveys of market participants indicate that they
place more emphasis on technical analysis (and less on fundamental analysis)
the shorter the time horizon; however, the technical analysis literature to
date has focused on long-term technical trading rules. We find, using two
bootstrap methodologies, that none of the 7846 popular technical trading
rules we test are profitable after data snooping bias is taken into account.
There is no evidence that the market is inefficient over this time horizon.