Finally, keep in mind that if trading on margin—which means you're borrowing your investment funds from a brokerage firm (and bear in mind that margin requirements for day trading are high)—you're far more vulnerable to sharp price movements. Margin helps to amplify the trading results not just of profits, but of losses as well if a trade goes against you. Therefore, using stop losses is crucial when day trading on margin.

You might hear experienced investors talk about the concept of a "wide moat," especially if you're reading anything about Warren Buffett's investment style. Just as a wide moat around a castle makes it difficult for enemies to invade, a company should have a "wide moat," too: a sustainable competitive advantage that will prevent competitors from stealing that company's market share.

P/E ratio -- The price-to-earnings ratio is the most widely cited valuation metric, and for good reason. It's an easy way to compare similar businesses. Simply divide a company's current share price by its last 12 months' worth of earnings. You can also use the projected earnings over the next 12 months to calculate the forward P/E ratio. The key point to know is that P/E ratios are most useful when comparing businesses in the same industry -- such as comparing ExxonMobil (NYSE:XOM) and Chevron (NYSE:CVX).
After going through a bear market in Q4 of 2018, on Jan. 4, the market posted a follow-through day to launch a new market uptrend, driving solid gains over the next several months. The market then pulled back again May 2019 before again continuing higher. This is just one example of how these types of stock market cycles continually repeat. Learning how they work and how to handle them using proven rules is key to long-term success..
When you buy a stock, you should have a good reason for doing so and an expectation of what the price will do if the reason is valid. At the same time, you should establish the point at which you will liquidate your holdings, especially if your reason is proven invalid or if the stock doesn’t react as expected when your expectation has been met. In other words, have an exit strategy before you buy the security and execute that strategy unemotionally.
Competition has spurred many brokerages to slash commission fees, which can add up quickly if you buy and sell stocks, mutual funds or ETFs frequently. Robinhood is not the only company that does not charge commission fees. Starting in October, Interactive Brokers is providing an unlimited number of commission-free trades on U.S. exchange-traded stocks and ETFs along with no account minimums or inactivity fees.
When investing in the stock market, you have to think long term and avoid the temptation to check your portfolio several times per day. All this will do is waste your time, stress you out, and increase the odds that you will make a big mistake and sell at the wrong time. Plan to set up automatic contributions to your investment so you can buy more investments no matter where you are.
But building a diversified portfolio of individual stocks takes a lot of time, patience and research. The alternative is a mutual fund, the aforementioned ETF or an index fund. These hold a basket of investments, so you’re automatically diversified. An S&P 500 ETF, for example, would aim to mirror the performance of the S&P 500 by investing in the 500 companies in that index.
Rarely is short-term noise (blaring headlines, temporary price fluctuations) relevant to how a well-chosen company performs over the long term. It’s how investors react to the noise that really matters. Here’s where that rational voice from calmer times — your investing journal — can serve as a guide to sticking it out during the inevitable ups and downs that come with investing in stocks.