Stock prices have begun a new tradition of rallying smartly in the final hour of trading. While the pattern doesn't hold true every day, it has been happening often enough to catch the attention of professional traders.

One Chicago stock index futures trader said that after 3 p.m. New York time, the stock and stock futures markets often come to life, thanks to the efforts of professional traders.

Stocks and stock futures have generally been rallying from 3 to 4 p.m. on days when trading is slow, excitement at a minimum and the majority of professional traders seemingly asleep at their desks. Without any strong pattern on either the buy or sell side, professional traders are able to step into the void and move the markets higher.

On most occasions, the move isn't big enough to make the next day's headlines. But it is substantial enough for traders who have caught on to this pattern to go home a little happier.

"Professional traders in the stock index futures market are trying to bully the financial markets to a level that will draw in buyers," said William King, an independent trader who spent many years on Wall Street and now tracks the stock index futures markets. "And if you are going to bully the market, you have to bully it as late in the day as possible."

King said this strategy is less likely to backfire on a "bully" if he waits for the last hour before starting to buy. "You want to create an emotional move and give other people less time to think," he added.

Bad timing may have been to blame for the surprise 45-point drop in the Dow Jones industrial average on June 22. The Dow was up about 23 points at 2:50 p.m. that day, despite what had been a very boring session. But almost the entire rally happened between 2:15 and 2:50 p.m.

The buyers who were being pulled into the market that day seemed to have too much time to reconsider what they were doing before trading ended. Without any apparent cause, the Dow suddenly reversed and finished that session with a loss of nearly 45 points -- an incredible 68-point swing in less than two hours.

Most of the time, however, the bullying has worked. A chart of trading in the Standard & Poor's 500 stock index futures contracts for May 8, for instance, shows that the bullies started pushing the market up at precisely 3:47 that afternoon and continued until trading ended in the S&P futures contract at 4:15 p.m. The Dow, meanwhile, gained nearly a dozen points that session, with 10 points coming in the last hour.

The pattern repeated on May 16, when the S&P futures contracts began rising sharply at about 2:57 p.m. The Dow was down 5.55 points at 3 p.m. in an ordinary session. But the index suddenly spurted when the final hour began and the Dow had a 7.87 gain by 3:30. Futures contracts went down very late that day, so the Dow finished with a 2.77-point loss.

On May 15, the day's big rally in stock index futures prices began at about 3:24 p.m.; on May 10 at about 3; on May 8 at about 3:45; on May 22 at about 3:24; on June 13 at about 3:15; and on June 11 at about 3:40. Those are just some of the days that produced a final-hour celebration.

Except for days when news events overwhelmed traders, the final hour buying binge has continued.

Last Monday, for instance, the stock market closed lower on fears that interest rates might rise. But between 4 and 4:15 p.m. -- after the stock market had closed for the day -- traders inexplicably pushed the price of stock index futures contracts sharply higher. That push almost guaranteed that stock prices would open strong on Tuesday morning, and they did.

(President Bush's comment that he would accept new taxes as part of a federal budget compromise gave the stock market a second reason to rise on Tuesday morning. But the rise in the futures the day before laid the groundwork.)

It isn't unusual for traders to try to bully stock prices higher late in the day. In fact, it's almost a tradition. But prior to the advent of stock index futures contracts, the traders would have to bully each individual stock. Nowadays, they have to bully only the Standard & Poor's 500 stock index futures contracts to have an impact on the whole market.

Can a small investor make money playing this final hour phenomenon? Probably not. Traders are usually crafty enough to change their modus operandi once it has been detected.

What credit crunch? That's the question Hanson Industries was undoubtedly asking itself when it recently went to banks to borrow $2.6 billion to complete an acquisition. The banks were willing to come up with $6 billion. Hanson took just the $2.6 billion because it apparently doesn't have any hot deals in the works. But that doesn't mean that Hanson, like other corporate acquirers, is getting out of the takeover business. "Hanson always has deals pending. They are always looking and people always bring deals to them," said a source.

John Crudele is a columnist for the New York Post.