The number of Harvard Business School (HBS) grads who take jobs on Wall Street might be an important contrarian financial indicator, according to banking industry analyst Roy Soifer, who was profiled today by Yahoo! Finance. Soifer follows the percentage of HBS grads who enter finance, and when 30% or more of HBS grads go into what he calls “market-sensitive positions”—hedge funds, investment banking, private equity, etc.—he sees this as a long-term “sell” signal. Notably, the class of 2010 saw 31%-32% of graduates taking these types of financial services jobs. Soifer, who has been examining this data for decades, believes this 30% tipping point is important, because business students respond to incentives: when industries are robust and “confident,” they hire aggressively and compete, potentially showing that they are ripe for a fall. Of course, this indicator is not foolproof, especially when it comes to timing. When Soifer saw a rise in the number of Harvard MBAs taking jobs on Wall Street in 2005, he indicated the market was due for a slowdown, but that trend was not realized until two years later.