you have to distinguish between making a capital gain or income ! if you are a trader then by definition your trades are usually not capital in nature, but revenue. any gains are included in your taxable income and taxed as such. any losses can be offset against gains. however if you have purchased shares with a view of long term investment (SARS uses a guideline of > 3 years and yes, even traders can have long term investments) then any gain or loss can be declared as capital in nature. (ie no normal income tax payable on gains) for the year ended feb 2008, the tax exempt gain for capital gains tax (NOT income tax) was 15000 pa which was increased to 16000 pa for the 2009 tax year. capital losses can as far as i know only be off-set against capital gains.