Up, down, left, right -- everyone wants to know which way the market's heading. Alas, that question rarely does investors any good.

Articles that try to predict the market's movements can get downright silly. One recently began: "The SPDR S&P 500 ETF (NYSE: SPY) has been influenced by the stock market this week." Well, duh. To a great extent, the S&P 500 index is the market, with its 500 components representing some 75% of the market capitalization of all U.S. stocks.

Many people do care how the S&P 500 will perform in the near future, but that's silly. Here are a few reasons why it's best to ignore short-term expectations of market movements:

  • Unless you're planning to buy or sell stocks this coming week, how the market does next week really won't matter. There are just two prices that determine how much you'll make (or lose) on a stock: The price at which you buy it, and the price at which you sell. (OK, sure, dividends you receive along the way matter, too.)
  • Single stocks don't necessarily follow the market. You're looking for a stock that can beat the market, succeeding even if some broader index doesn't go anywhere. Cisco Systems (Nasdaq: CSCO) is one attractively priced example right now. The company provides much of the backbone of a still rapidly expanding Internet, which Cisco predicts could grow traffic by at least 40% annually over the next five years. Elsewhere, Activision Blizzard (Nasdaq: ATVI) commands a top position in the $20 billion U.S. video game market, with growing market share and a 10-year deal with Halo creator Bungie. Will these stocks rise next week, or next month? Who knows? But over the long run, superior companies like these two have the best chance to bring you the best returns.
  • Obsessively monitoring the market, and seeking predictions of its performance, isn't the best use of your time. Focusing on the short term can lead you to ignore far more important long-term issues. Instead of planning a strategy for the future, you're essentially left gambling with your money on each day's ups and downs.

Micromanaging your money can also lead you to miss out on good gains. So don't worry about whether the market will rise or fall in the next few days. Instead, keep seeking great stocks and funds. When you know you want to buy or sell something, don't worry too much about the timing. Just do it.

Longtime Fool contributor Selena Maranjian owns shares of Activision Blizzard. The Fool owns shares of Activision Blizzard, which is a Motley Fool Stock Advisor pick. Motley Fool Options has recommended a synthetic long position on Activision Blizzard. Try any of our investing newsletter services free for 30 days. The Motley Fool is Fools writing for Fools.