xoli, if you only trade and intend to declare your gains as trading gains, then based on your scenario you will very simply pay tax per the individual tax tables for personal income (as per the link supplied by marc) on your profit, in this case 500 000.- without any deductions this would work out to just on 194K. of course you could make this more ineteresting by taking interest earning exemptions in your personal capacity, deducting your allowables like med aid caps if you have and pay for med aid, deduct home office expenses if you work from home...........