In the movie “A Beautiful Mind,” a math genius becomes obsessed with patterns, believing he detects spy messages hidden in ordinary newspaper and magazine articles.

It’s a good movie for investors right now because we’re hearing a lot of mumbo jumbo about patterns in the stock market. For soothsayers, astrologers and stock-market chartists, bad times can be good times people are desperate for insight.

At the extremes, there are those who believe they can predict the market’s future from the patterns in a fever chart tracing stocks’ ups and downs. If the market hits a low, as it did in July, then recovers a bit, as it did in August, then drops again, as it has recently, it has “found the bottom” and is ready for a big rebound. So the theory goes.

Others, looking at past patterns, assert that certain sectors, or types of stocks, tend to rebound first. Hence, investors should pour their money into those.

Granted, there must be some patterns that really do represent cause-and-effect relationships that might repeat themselves. But if they are detected and widely publicized, their usefulness for investing purposes is ruined. Investors rush to buy the bargain stocks that are expected to jump.

The heightened demand pushes prices up until the stocks aren’t bargains anymore. Every time the cycle is repeated, investors pile into the bargains earlier and earlier, gradually destroying the pattern.

This happened, for example, to the Dogs of the Dow strategy. Some years ago, historical evidence showed investors could make market-beating returns by buying the 10 stocks among the 30 in the Dow Jones industrial average that had the highest dividend yield, or annual dividend divided by share price. In effect, high yield was a way of identifying stocks whose prices had fallen to unusual lows and were, thus, poised for outsized gains.

The Dogs strategy did work for a while. But as more investors tried it, the bargains started to disappear too quickly. For the past five years, the Dogs have trailed the overall market. You don’t hear much about the Dogs strategy these days.

If there were a sure way to use patterns to predict the market, everyone would act on it and the patterns would be broken. Is there, then, a better way to forecast?

While nothing is certain, it’s worth remembering why people buy stocks to get a share of a company’s profits, now or in the future. Sure, you might buy stock in a money-losing company, but only because you think there’s enough chance of profits someday to cause other investors to pay more for your shares than you did.

Given this, the immediate future from now to the end of the year looks bleak. The grim economic news, such as the poor retail sales reported last week, suggests corporate earnings aren’t about to soar.

Also, a number of factors weigh on investor psychology.

There still seems to be considerable concern about the accuracy of corporate financial statements. Getting free of this may require more aggressive accounting reform and perhaps a full fiscal year free of major new scandal. Until this worry dissipates, investors will be reluctant to pour money into stocks even if there is some sign profits are growing.

Certainly, many investors also are worried about the possibility of terrorist attack.

Perhaps more significant, though, are the prospects of war in Iraq, which would surely be bad for the market. Even if Saddam Hussein could be quickly dispatched, changing Iraq into a friendly nation could take far longer than it took to liberate Kuwait in 1991, and it could cost much more. If we go to war in Iraq, the stock market could be depressed for years.

It’s probably fair to assume, though, that stocks will rise over time. In five years, or perhaps 10, the Dow and Standard & Poor’s 500 may well be significantly higher than they are today, though it’s fair to wonder whether the Nasdaq, now around 1300, will ever climb back to 5000.

Making a positive long-term prediction, however, is basically an act of faith. Yes, stocks have always gone up over long periods. But counting on that is to depend on a pattern repeating itself, and there’s no guarantee it will.

To have faith in the long-term value of stocks, you have to believe America has a good economic system, that we will remain competitive internationally, that technology will make workers more productive, that we won’t be pummeled by a mile-wide asteroid …

You have to have faith that profits eventually will grow and that stock prices will then move up. There’s no guarantee such faith will be rewarded, but the odds are good enough for me.