ECN/Level 2 quotes: ECNs, or electronic communication networks, are computer-based systems that display the best available bid and ask quotes from multiple market participants and then automatically match and execute orders. Level 2 is a subscription-based service that provides real-time access to the Nasdaq order book composed of price quotes from market makers registering every Nasdaq-listed and OTC Bulletin Board security. Together, they can give you a sense of orders being executed in real time.
The Momentum and Reversal trading strategies are the #1 and #2 best trading strategies out there. These two day trading strategies are being used by thousands of our students who have participated in the Warrior Trading Day Trading Courses. In fact, in a survey of 100 of these students, over 80% are now trading profitably thanks to these strategies (click here for survey details) These strategies can be the basis for your $200/day trading plan.
The common use of buying on margin (using borrowed funds) amplifies gains and losses, such that substantial losses or gains can occur in a very short period of time. In addition, brokers usually allow bigger margin for day traders. In the United States for example, while the initial margin required to hold a stock position overnight are 50% of the stock's value due to Regulation T, many brokers allow pattern day trader accounts to use levels as low as 25% for intraday purchases. This means a day trader with the legal minimum $25,000 in his account can buy $100,000 (4x leverage) worth of stock during the day, as long as half of those positions are exited before the market close. Because of the high risk of margin use, and of other day trading practices, a day trader will often have to exit a losing position very quickly, in order to prevent a greater, unacceptable loss, or even a disastrous loss, much larger than her original investment, or even larger than her total assets.
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").
The key to scalping while using short time frames is to identify price changes before the rest of the market has had the chance to act. You should also be willing to accept very low profit margins—gaining less than 1% on a given action will still usually be in your best interest. Because of this, many scalpers may implement tight stop-loss and stop-limit orders over time.
The price movements of any stock are posted throughout the trading day and summarized at the end of the trading day. For example, April 2, 2019, shares of Apple Inc. (AAPL) opened at $191.09 and closed at $194.02. During the day, as indicated in the "day's range" listed to the right of the closing price, shares dropped as low as $191.05—the intraday low—and hit a peak of $194.46—the intraday high.
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.” 
Scalpers buy low and sell high, buy high and sell higher, or short high and cover low, or short low and cover lower. They tend to utilize Level 2 and time of sales windows to route orders to the most liquid market makers and ECNs for quick executions. The point-and-click style execution through the Level 2 window or pre-programmed hotkeys are the quickest methods for the speediest order fills. Scalping is purely based on technical analysis and short-term price fluctuations. Due to the extensive use of leverage, scalping is considered a high-risk style of trading.
Day traders are attuned to events that cause short-term market moves. Trading the news is a popular technique. Scheduled announcements such as economic statistics, corporate earnings or interest rates are subject to market expectations and market psychology. Markets react when those expectations are not met or are exceeded, usually with sudden, significant moves, which can benefit day traders.
Some of the common mistakes that scalpers make are poor execution, poor strategy, not taking stop-losses, over-leveraging, late entries, late exits and overtrading. Scalping generates heavy commissions due to the high number of transactions. A per-share commission pricing structure is beneficial to scalpers, especially for those who tend to scale smaller pieces in and out of positions.
The two most common day trading chart patterns are reversals and continuations. Whilst the former indicates a trend will reverse once completed, the latter suggests the trend will continue to rise. Understanding these trading patterns, as well as ‘triangles’, ‘head and shoulders’, ‘cup and handle’, ‘wedges’ and plenty more, will all make you better informed when it comes to employing your trading strategies.