There is a curiously persistent gap between the total number of investors according to exchanges and depositories and income tax statistics.
Income tax statistics released for the assessment year (AY) 2015-16 showed that less than a million (733,940) entities reported short-term capital gains or losses. This is much lower than the total number of demat accounts (23 million) and active stock market traders (5 million) in the corresponding period.
The income tax department has been periodically releasing annual tax statistics. Its latest release covers assessment year (AY) 2015-16. The assessment year is one year ahead of the financial year (FY). So AY16 refers to income from FY15.