Stock prices are down and likely to go lower if the economy continues to wither. But that little fact isn't keeping the more creative folks on Wall Street from one annual recreation -- devising ways to profit from year-end quirks in the stock market.

Oppenheimer & Co., for instance, recently picked thousands of stocks that have dropped sharply in price and ran them through a computer program to try to determine which may be down by an excessive amount simply because investors want to claim losses on their 1990 tax returns. The theory behind this exercise is that once tax-selling pressure is off these stocks, their prices will rise.

Michael Metz, chief market analyst for Oppenheimer, said this process historically has worked well. The only problem recently is that investors are jumping the gun.

"Investors have become so sophisticated that they now buy stocks in November and early December, which in itself causes a rally in stocks that otherwise would have had their bounce in January," he said. His favorite picks this year are Aluminum Co. of America, Amax Inc., PACCAR Inc., Communications Satellite Corp. and Phelps Dodge Corp.

Over the years, investors have noticed that stock prices tend to rally in the first few days of January, mostly because tax selling is out of the way, but also because many professional and private investors enter a new year with smiles on their faces. Yale Hirsch, a stock market historian, has also noticed that when stocks rise in the first few days of a new year, they also tend to be higher for the year as a whole.

Now that everybody knows that stocks have a better than even chance of prospering in early January, they spend much of December trying to decide which stocks to add to their portfolios and when to add them.

Blue-chip stocks like International Business Machines Corp. and General Motors Corp. are favorite December acquisitions because the stock market is unlikely to rally in January without them. (Shares of top companies are also buoyant in very late December because money managers try to replace the whipped dogs in their portfolios with greyhounds before they have to report their activities to clients.)

William King, an independent trader who spent years with foreign investment firms, said the Japanese tend to convert their dollar investments into yen at the end of the calendar year.

What this does, King said, is keep downward pressure on the U.S. dollar at the end of the year. And while this may push down the profits and share prices of U.S. companies with massive foreign operations, it also means that these stocks should rally nicely in the new year if the pressure on the dollar ceases.

Another quirk: Experts say that bonds tend to rally in late November and early December because companies wait until late in the year to move money into employee pension funds. This money often ends up being invested in bonds, pushing up prices.

A shrewd investor with excellent timing, the theory goes, could ride the bonds higher and get out before they weaken again in January.

If you are thinking of playing any of these year-end games, there are a few things you should keep in mind. First, the nation's economy and banking system are in trouble and investment gimmicks might not work this time around. And even if the gimmicks do work, a successful investor has to have perfect timing -- like the first people in a Ponzi scheme.

And by the time you have read this, it's probably already too late. The rally that the stock market has experienced these past few weeks could very well have been the result of the gimmicks mentioned above.

John Crudele is a columnist for the New York Post.