NEW YORK (CNN/Money) - The New England Patriots kept their postseason winning streak intact Sunday. Now investors will have to hope the Super Bowl stock market indicator's losing streak also keeps going.

The Patriots beat the Philadelphia Eagles in the Super Bowl Sunday evening 24-21, giving the team nine straight postseason wins and three championships over the last four years.

Besides fans in New England, the bears should be happy about that as well -- not the football team in Chicago, but those investors who are looking for a decline in U.S. stocks. That's because the Super Bowl indicator, which is based on the history of the winning team in the big game, would suggest a down year for stocks in 2005.

According to the formula, a win by a team that played in the old National Football League would give a lift to stocks. A championship by a team like the Patriots that played in the American Football League before the merger of the two circuits would let the bears run.

But the indicator, which had about a 90 percent success rate predicting the market in its first XXXI years of existence, has had only one clean win in the past VII big games before Sunday.

In 2002, the win by Patriots accurately foretold the continuation of the bear market into a third year. But when the Pats won again in 2004, it didn't bring on another bear market. A fall rally helped push stocks into positive territory, sacking the indicator for another loss.

Of course even when the indicator seemed to be working, it was far safer to watch a football game in Philadelphia or New England wearing the opposing team's colors than it was to base investment decisions on it.

Even so, Bob Stovall, who helped popularize the Super Bowl indicator in the 1970s when he served as investment policy director at Morgan Stanley predecessor Dean Witter Reynolds, isn't ready to give up on it.

"It's been correct just under 80 percent of the time," he said recently. "I don't know of any other gaggle of gurus that has a record that good. Of course, I certainly wouldn't put real money into the market based on the game. But it's nice to know if it's on your side."

Stovall, now managing director and strategist at Wood Asset Management in Sarasota, Fla., is a University of Pennsylvania grad who was pulling for the Eagles -- an old NFL team -- even without the indicator making that the bullish call.

Other traders and market observers are still fans of the indicator -- though they aren't always faithful.

"I've always enjoyed it as a football fan," said Jeff Hirsch of the Stock Trader Almanac. "But as a market analyst, I always turn to our January barometer."

That indicator, which says that as January goes, so goes the markets for the full year, has been right 80 percent of the time since 1938, said Hirsch. He says the track record is even better in years following a presidential election, as the market reacts to the agenda of the newly elected or re-elected president.

The January effect indicator and Super Bowl indicator are in synch this year, as a 2.5 percent decline for the Standard & Poor's 500 index in January also suggests this will be a tough year for stocks.

Even so, there's hope for bullish investors, since at least the Super Bowl indicator has been wrong so many times recently. But before the final gun is sounded on the indicator, realize there's a reason to disregard some of its recent failures, and to worry that it is ready to get back on track.

The indicator hasn't had many clean readings the past few years, due to expansion teams and nomads making it to the big game.

In four of the past five years, including last year, at least one of the teams in the Super Bowl was formed after the merger, or changed its name when it moved.

The only year that you had two teams meet whose names would be recognized at the time of the merger was in 2002, when the Patriots beat the Rams, and the indicator correctly predicted another loss for the markets.

This year was another one of those clean tests. Patriots vs. the Eagles, AFL versus NFL. If stocks lose ground this year, maybe the lesson is to ignore the years which don't fit this relatively clean test.

But whether or not the winner correctly calls the direction of the market, you can be sure it'll be talked about again next year. What else is there to do on Wall Street in the cold, dark days of February following the Super Bowl?