In March 2000, this bubble burst, and a large number of less-experienced day traders began to lose money as fast, or faster, than they had made during the buying frenzy. The NASDAQ crashed from 5000 back to 1200; many of the less-experienced traders went broke, although obviously it was possible to have made a fortune during that time by short selling or playing on volatility.
If the market is trending down, they would short securities that exhibit weakness when their prices bounce. Most independent day traders have short days, working two to five hours per day. Often they will practice making simulated trades for several months before beginning to make live trades. They track their successes and failures versus the market, aiming to learn by experience.
If the strategy is within your risk limit, then testing begins. Manually go through historical charts to find your entries, noting whether your stop loss or target would have been hit. Paper trade in this way for at least 50 to 100 trades, noting whether the strategy was profitable and if it meets your expectations. If it does, proceed to trading the strategy in a demo account in real time. If it's profitable over the course of two months or more in a simulated environment, proceed with day trading the strategy with real capital. If the strategy isn't profitable, start over.
But there is an added risk with the shorter time frame. A wide spread between the bid, the ask and commissions can eat too large a portion of your profits. Swing traders can struggle with this too, but the effect is amplified for the day trader. Day traders can find themselves doing all the work, and the market makers and brokers reap the benefits.
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.