No — late filers face higher tax rates only on property transactions, not on dividends or stock investments.
For dividends, you will be taxed at the normal rate, same as an active filer.
Capital gains on stocks are also charged at standard filer rates, not penalized.
Mutual fund investments are similarly taxed at regular filer rates.
So in your case, you will be treated the same as an active filer for stocks and mutual funds.