Why don't governments take a portion of the stock as tax payment? They can cash it in (or not), but if all your money is in stocks, are they forcing you to sell the stock to pay them? i.e.: The tax shouldn't be in numerated in currency but stock. If it is currency, you are forced to measure a portion of the stock based on its current value and sell that much stock, if they take a fixed percent of the stock that amount could be a lot or not so much depending on the value of the stock when they tax you. The amount of tax you pay shouldn't depend on how well the stock is doing at taxation time.