This morning we noted that forty percent of the MBA class of 2007 from Harvard Business School headed to Wall Street to take "market sensitive" jobs. This is dire news for stocks, according to Ray Soifer. When that number climbs above 30%, the market is sending a long-term sell-signal, Soifer argues. We first hit 30% in 2005 (only 24% of the class of 2004 took such jobs), and last year's number was 37%.

Of course, skeptics of Soifer's metric might point out that the S&P 500 is up something like 25% since the sell indicator came out. But he cautions that his indicator has a lot of disadvantages: it only comes out once a year, and is intended as a long-term indicator and not a predictor of the immediate funture.

"Yet, for long-term investors who can think in terms of decades rather than months or quarters, it's worth keeping an eye on," Soifer notes. "Besides, it's fun!"

(Note: Our most loyal readers might wonder why we initially reported the number had jumped from 37% to 44% but we've now revised this year's number down to 40%. Our reason is rather simple. Soifer counts only "market sensitive" jobs in his metric, not the overall number of HBS MBAs headed to finance. Our initial report of 44% counted all finance jobs, while the 37% counted market-sensitive jobs (the over-all number in 2006 was 42%). This created the impression that the climb was even more extreme than it actually was. But, we should note, that the gap between the "market sensitive" jobs and the overall finance jobs is closing.)