Liquidity - The liquidity of a market affects the performance of scalping. Each product within the market receives different spread, due to popularity differentials. The more liquid the markets and the products are, the tighter the spreads are. Some scalpers like to trade in a more liquid market since they can move in and out of large positions easily without adverse market impact. Other scalpers like to trade in less liquid markets, which typically have significantly larger bid-ask spreads. Whereas a scalper in a highly liquid market (for example, a market maintaining a one-penny spread) may take 10,000 shares to make a 3 cent gain ($300), a scalper in an illiquid market (for example, a market with a 25 cent spread) may take 500 shares for a 60 cent gain ($300). While there is theoretically more profit potential in a liquid market, it is also a "poker game" with many more professional players which can make it more difficult to anticipate future price action.
This strategy is mostly only done by day traders. It requires that you have access to one to several real-time news sources and can make split second decisions. News and rumors can provide large amounts of volatility and high emotion creating great opportunities if traded properly. The biggest challenge of trading this strategy is anticipating the market’s reaction to the news and how it effects the price of the stock. Click here for more information on trading news and rumors.
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.
Financial settlement periods used to be much longer: Before the early 1990s at the London Stock Exchange, for example, stock could be paid for up to 10 working days after it was bought, allowing traders to buy (or sell) shares at the beginning of a settlement period only to sell (or buy) them before the end of the period hoping for a rise in price. This activity was identical to modern day trading, but for the longer duration of the settlement period. But today, to reduce market risk, the settlement period is typically two working days. Reducing the settlement period reduces the likelihood of default, but was impossible before the advent of electronic ownership transfer.
Much research on historical data has proven that, in a market conducive to swing trading, liquid stocks tend to trade above and below a baseline value, which is portrayed on a chart with an EM). In his book, "Come Into My Trading Room: A Complete Guide to Trading" (2002), Dr. Alexander Elder uses his understanding of a stock's behavior above and below the baseline to describe the swing trader's strategy of "buying normalcy and selling mania" or "shorting normalcy and covering depression." Once the swing trader has used the EMA to identify the typical baseline on the stock chart, he or she goes long at the baseline when the stock is heading up and short at the baseline when the stock is on its way down.
Scalpers use technical analysis but within this style, can be either discretionary or system traders. Discretionary scalpers will make each trading decision in real time (albeit very quickly), whereas system scalpers follow a scalping system without making any individual trading decisions. Scalpers primarily use the market's prices to make their trading decisions, but some scalpers also use one or more technical indicators, such as moving averages, channel bands, and other chart patterns.
The swing trader, therefore, is best positioned when markets are going nowhere – when indexes rise for a couple of days, then decline for the next few days, only to repeat the same general pattern again and again. A couple of months might pass with major stocks and indexes roughly at the same place as their original levels, but the swing trader has had many opportunities to catch the short-term movements up and down (sometimes within a channel).

You're probably looking for deals and low prices, but stay away from penny stocks. These stocks are often illiquid, and chances of hitting a jackpot are often bleak. Many stocks trading under $5 a share become de-listed from major stock exchanges and are only tradable over-the-counter (OTC). Unless you see a real opportunity and have done your research, stay clear of these.