(MONEY Magazine) – It's not the type of investing you should try at home, but Yale University has managed what few other schools have.

In a year when every major stock index has tanked, the Ivy League school's $10 billion endowment is up 9.2% for the year ended June 30 (the date Yale reports its annual results). The S&P 500, by comparison, was down 15.7% during that period, and the Nasdaq plummeted 46.4%. Other schools, among them the University of California and Duke, are sitting on losses of up to 25%.

How did Yale do it? David Swensen, Yale's director of investments, won't say, but Mary Peloquin-Dodd, an analyst with Standard & Poor's, says diversification was the key to Yale's success.

That and plenty of guts: A full 25% of Yale's portfolio is in private equity. These direct investments in small companies perform more like venture capital than stocks. Another 15% of the portfolio is stashed away in hard assets, such as real estate, paper and chemicals. All in all, it's a fairly big change from a decade ago, when 70% of Yale's portfolio was invested in the old standbys--stocks, bonds and cash.

Plus, says S&P's Peloquin-Dodd, Swensen has been holding short positions in the portfolio. Yale won't disclose specific names. But that's not surprising, considering the potential fallout: Short positions, after all, can give the impression that a university is betting against companies owned by its own precious benefactors.

--ILANA POLYAK