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).
Blue-chip stocks are popular because they typically have a decades-long track record for earning. "Blue chips" derived their name from Poker, where the most valuable playing chip color is blue. Shareholders like them because they tend to grow dividend rates faster than the rate of inflation meaning the owner increases income without having to buy another share. Blue-chip stocks are not flashy, but they have solid balance sheets and steady returns.
By knowing how much capital you will need and the future point in time when you will need it, you can calculate how much you should invest and what kind of return on your investment will be needed to produce the desired result. To estimate how much capital you are likely to need for retirement or future college expenses, use one of the free financial calculators available over the Internet.
Notice: Information contained herein is not and should not be construed as an offer, solicitation, or recommendation to buy or sell securities. The information has been obtained from sources we believe to be reliable; however no guarantee is made or implied with respect to its accuracy, timeliness, or completeness. Authors may own the stocks they discuss. The information and content are subject to change without notice.

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.
Buy “the basket”: Can’t decide which of the companies in a particular industry will be the long-term winner? Buy ’em all! Buying a basket of stocks takes the pressure off picking “the one.” Having a stake in all the players that pass muster in your analysis means you won’t miss out if one takes off, and you can use gains from that winner to offset any losses. This strategy will also help you identify which company is “the one” so you can double down on your position if desired.