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.
There are two primary divisions of professional day traders: those who work alone and/or those who work for a larger institution. Most day traders who trade for a living work for a large institution. These traders have an advantage because they have access to a direct line, a trading desk, large amounts of capital and leverage, expensive analytical software, and much more. These traders are typically looking for easy profits that can be made from arbitrage opportunities and news events, and these resources allow them to capitalize on these less risky day trades before individual traders can react.
The tick volume is measured by how much the price is has ticked “up” or “down” in that particular candle bar. So the more people are getting in at the time, the longer the volume line will become. This is because there will be more movement in price action with all of those entry orders flying in. So it makes sense that the volume indicator is, first of all, very accurate, and second has no real lag to it. It is currently showing you what the price action is doing the number of “ticks” on that candle bar. This results in the bar looking like this:
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.
There is a lot of hype around day trading. Some websites promote it as a way to get rich quick (it isn't), and others say it is impossible (also not true). There are lots of day traders around the world who find success and make a living off the markets, so the truth lies somewhere in between those two extremes. If you've thought about day trading, it's worth your time to read through and understand the concepts discussed below, so you'll be better prepared for what to expect if you decide to proceed.
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.