Day trading is defined as the purchase and sale of a security within a single trading day. It can occur in any marketplace but is most common in the foreign exchange (forex) and stock markets. Day traders are typically well-educated and well-funded. They use high amounts of leverage and short-term trading strategies to capitalize on small price movements in highly liquid stocks or currencies.
As with any other style of trading, many different methods of scalping exist. The most well-known scalping technique is using the market's time and sales to determine when and where to make trades. Scalping using the time and sales is sometimes referred to as tape reading because the time and sales used to be displayed on the old-fashioned ticker tape, known as the tape.
Scalping can be very profitable for traders who decide to use it as a primary strategy, or even those who use it to supplement other types of trading. Adhering to the strict exit strategy is the key to making small profits compound into large gains. The brief amount of market exposure and the frequency of small moves are key attributes that are the reasons why this strategy is popular among many types of traders.

The first 9 successful trades produce $900 in profit. On the 10th trade, when the position is down $50, instead of except the loss the untrained trader purchases more shares at a lower price to reduce his cost basis. Once he is down $100, he continues to hold and is unsure of whether to hold or sell. The trader finally takes the loss when he is down $1,000.
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.
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.