daytraders don't hold on to stocks for too long, maybe a day or an hour. say you buy 1000 shares of a stock and it goes up .50 cent you make $500 once you sell it at the high price. but usually the stock only fluctuates .10 cent - .40 cent, unless there's a major announcement like quarterly earnings or a merger. do that 1-5 times a day and you could make a living day-trading. either you short the stock or bet that it will go up. remember to save some $$$ for taxes off what you earn.