Many professional money managers and financial advisors shy away from day trading arguing that, in most cases, the reward does not justify the risk. Conversely, those who do day trade insist there is profit to be made. Day trading profitably is possible, but the success rate is inherently lower because of the complexity and necessary risk of day trading in conjunction with the related scams. Moreover, economists and financial practitioners alike argue that over long time periods, active trading strategies tend to underperform a more basic passive index strategy, especially after fees and taxes are taken into account.
The common use of buying on margin (using borrowed funds) amplifies gains and losses, such that substantial losses or gains can occur in a very short period of time. In addition, brokers usually allow bigger margin for day traders. In the United States for example, while the initial margin required to hold a stock position overnight are 50% of the stock's value due to Regulation T, many brokers allow pattern day trader accounts to use levels as low as 25% for intraday purchases. This means a day trader with the legal minimum $25,000 in his account can buy $100,000 (4x leverage) worth of stock during the day, as long as half of those positions are exited before the market close. Because of the high risk of margin use, and of other day trading practices, a day trader will often have to exit a losing position very quickly, in order to prevent a greater, unacceptable loss, or even a disastrous loss, much larger than her original investment, or even larger than her total assets.
A trader can measure their performance as a percentage of the trading channel width. The perfect trade would be buying at the bottom channel line and selling at the top channel line, which would be a 100% performance. If a trader captured one-half of the channel, it would be a 50% performance. The goal is to continually increase the performance percentage of the average winning trade.
Once you have a specific set of entry rules, scan through more charts to see if those conditions are generated each day (assuming you want to day trade every day) and more often than not produce a price move in the anticipated direction. If so, you have a potential entry point for a strategy. You'll then need to assess how to exit, or sell, those trades.
Assess how much capital you're willing to risk on each trade. Many successful day traders risk less than 1% to 2% of their account per trade. If you have a $40,000 trading account and are willing to risk 0.5% of your capital on each trade, your maximum loss per trade is $200 (0.005 x $40,000). Set aside a surplus amount of funds you can trade with and you're prepared to lose. Remember, it may or may not happen.