Whatever happens on a stock exchange and no matter how much influence computers, algorithms and high frequency trading may have, human nature will always have an important role to play. Typically, human nature becomes more important when momentum is changing and there is excitement or panic in the air. It would seem wise to try and understand this mass psychology or group thinking which is often referred to by investors as the madness of crowds.

Phrases like “earnings movers” and “intraday highs” don’t mean much to the average investor, and in many cases, they shouldn’t. If you’re in it for the long term — with, say, a portfolio of mutual funds geared toward retirement — you don’t need to worry about what these words mean, or about the flashes of red or green that cross the bottom of your TV screen. You can get by just fine without understanding the stock market much at all.
Even when the stock price has performed as expected, there are questions: Should I take a profit now before the price falls? Should I keep my position since the price is likely to go higher? Thoughts like these will flood your mind, especially if you constantly watch the price of a security, eventually building to a point that you will take action. Since emotions are the primary driver of your action, it will probably be wrong.
A market index tracks the performance of a group of stocks, which either represents the market as a whole or a specific sector of the market, like technology or retail companies. You’re likely to hear most about the S&P 500, the Nasdaq composite and the Dow Jones Industrial Average; they are often used as proxies for the performance of the overall market.
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.