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.
Scalping is the shortest time frame in trading and it exploits small changes in currency prices. Scalpers attempt to act like traditional market makers or specialists. To make the spread means to buy at the Bid price and sell at the Ask price, in order to gain the bid/ask difference. This procedure allows for profit even when the bid and ask don't move at all, as long as there are traders who are willing to take market prices. It normally involves establishing and liquidating a position quickly, usually within minutes or even seconds.
The systems by which stocks are traded have also evolved, the second half of the twentieth century having seen the advent of electronic communication networks (ECNs). These are essentially large proprietary computer networks on which brokers can list a certain amount of securities to sell at a certain price (the asking price or "ask") or offer to buy a certain amount of securities at a certain price (the "bid").
Finally, keep in mind that if trading on margin—which means you're borrowing your investment funds from a brokerage firm (and bear in mind that margin requirements for day trading are high)—you're far more vulnerable to sharp price movements. Margin helps to amplify the trading results not just of profits, but of losses as well if a trade goes against you. Therefore, using stop losses is crucial when day trading on margin.
As with bullish swing trades, if the reward-to-risk ratio is acceptable, you could enter your trade using a sell-stop limit order. This would result in selling the stock short once it hits your entry point. Selling short is the process of borrowing shares from your online broker and selling them in the open market, with the intention of purchasing the shares back for less cost in the future. An alternative to short selling would be to buy an in-the-money put option. If you choose to use options, you would use a contingent order to buy the put after the stock hit the entry price.
The goal of swing trading is to capture a chunk of a potential price move. While some traders seek out volatile stocks with lots of movement, others may prefer more sedate stocks. In either case, swing trading is the process of identifying where an asset's price is likely to move next, entering a position, and then capturing a chunk of the profit from that move.
Sincere interviewed professional day trader John Kurisko, Sincere states, Kurisko believes that some of the reversals can be blamed on traders using high-speed computers with black-box algorithms scalping for pennies. “That’s one of the reasons many traders get frustrated with the market. The timing is not like it used to be, and many of the old rules don’t work like before.” 
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.
In addition to knowledge of basic trading procedures, day traders need to keep up on the latest stock market news and events that affect stocks—the Fed's interest rate plans, the economic outlook, etc. So do your homework. Make a wish list of stocks you'd like to trade and keep yourself informed about the selected companies and general markets. Scan business news and visit reliable financial websites.