One well-known Wall Street guru recently pushed aside all the modern research he had been doing on the stock market and the economy and retreated to the library.

There he thumbed through old newspapers and magazines in an attempt to get a feel for the emotions that led to the stock market crash of 1929.

Not everyone on Wall Street is renewing their library cards. But the folks who made a living trading stocks and bonds this past decade are becoming increasingly interested in what economic downturns are supposed to feel like, and how the financial markets ordinarily react.

This isn't idle curiosity. There is some concern on Wall Street that the financial markets haven't reacted properly to this recent economic downturn because many of those wielding power either haven't yet experienced a bear market, or have forgotten what one is like.

Trader naivete would be all right, of course, if it continued to hold stock prices up forever. But just as the old soldier worries that the green recruits guarding his flank might suddenly make a mistake, some Wall Street veterans are wondering just how well the hotshots of the 1980s will react under fire.

Nobody will know what the hotshots are made of until the next war begins. But most of the veterans are expressing confidence in the troops behind them.

"The market is bigger than any group of people," said one old-time trader, who believes that Wall Street firms have been maintaining tighter control over the actions of all their traders. That additional monitoring, he believes, is a direct result of losses that some firms experienced in bond markets at the hands of green traders.

"There are obviously a significant number of veterans around who are in a position where they are watching what the novices are doing," said this trader.

Others are confident that everyone on Wall Street is up to speed, as they say, on their recession history. "It doesn't take too much research to see what things were like in previous recessions," said Charles Jensen of MKI Securities.

But have the traders been using those library cards?

IBM's second-quarter earnings, released a few weeks ago, looked incredibly good. In fact, more than one Wall Street report issued right after the figures were released called the quarter very strong.

Shares of the nation's largest computer manufacturer were selling in the vicinity of $123 each at around the time the earnings came out. Why, then, has IBM's stock lost more than $10 a share following such wonderful news?

It appears that IBM's woes are more than just a case of "selling on the news." When analysts started looking beneath the second-quarter numbers, and when they started listening to what other high-technology companies were saying about a slowdown in business, they appear to have been scared.

Take IBM's numbers first. The company's second-quarter profit was $2.45 a share, compared with $2.31 in the same quarter of 1989. Analysts estimate that because the dollar was weak for much of the second quarter, IBM's profits were helped by 20 cents a share.

So if the dollar had been neutral, IBM's earnings would have been down to $2.25 a share from $2.31. Not very good.

What's bothering analysts even more is the fact that the dollar hasn't been as weak so far in the third quarter as it was in the second quarter. So when IBM sells a computer overseas, it won't help earnings as much this time around.

And overseas earnings are IBM's strongest point right now. Analysts estimated that IBM sales grew around 13 percent internationally, but only a meager 1 percent to 3 percent in the United States.

IBM, of course, could also be hurt if the U.S. economy -- as expected -- continues to slow. Other technology firms, such as Texas Instruments, the computer chip manufacturer, have already warned Wall Street that business conditions are weak.

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John Crudele is a columnist for the New York Post.