Spreads are bonuses as well as costs - Stock Markets operate on a bid and ask based system. The numerical difference between the bid and ask prices is referred to as the spread between them. The ask prices are immediate execution (market) prices for quick buyers (ask takers); bid prices for quick sellers (bid takers). If a trade is executed at market prices, closing that trade immediately without queuing would not get you back the amount paid because of the bid/ask difference. The spread can be viewed as trading bonuses or costs according to different parties and different strategies. On one hand, traders who do NOT wish to queue their order, instead paying the market price, pay the spreads (costs). On the other hand, traders who wish to queue and wait for execution receive the spreads (bonuses). Some day trading strategies attempt to capture the spread as additional, or even the only, profits for successful trades.
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.
Intraday Trading Strategies require intermediate to an advanced level understanding of how different aspects such as intraday charts, trading indicators, candlestick patterns, intraday trading tricks work together. If you are a beginner, it makes total sense to understand at least the basics of these concepts instead of directly employing these strategies in your trades.
ECNs and exchanges are usually known to traders by a three- or four-letter designators, which identify the ECN or exchange on Level II stock screens. The first of these was Instinet (or "inet"), which was founded in 1969 as a way for major institutions to bypass the increasingly cumbersome and expensive NYSE, and to allow them to trade during hours when the exchanges were closed. Early ECNs such as Instinet were very unfriendly to small investors, because they tended to give large institutions better prices than were available to the public. This resulted in a fragmented and sometimes illiquid market.
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.