David Swensen has been called “Yale’s $8 billion man” for outperforming the average university endowment by that amount during the first 20 years of his tenure as Yale’s Chief Investment Officer. Chalk that outperformance up to the success of what’s become known as the “Yale model,” or the insight that institutional investors like endowments or pension funds can achieve outsize returns by allocating a large chunk of their assets to hedge funds, private equity, real estate, and other alternative investments.

As Swensen explained in a lecture he gave to Yale MBAs in 2008 , the Yale model rests on two core tenets: 1) “an equity bias for portfolios with a long time horizon,” because equities and equity-like alternative investments tend to rise in value in the long run; and 2) diversification, because by spreading investments among several asset classes with varying degrees of liquidity, ”for any given level of risk, you can increase the return.”

These days, though, it seems both of Swensen’s credos have become passé in the community of corporate pension fund managers, as Reuters’ Sam Forgione reported late last week:

For the first time in over a decade, more of the $1.246 trillion assets represented by the 100 largest U.S. corporate pension funds is now in bonds instead of equities, according to pension consulting firm Milliman…

“There will definitely be less demand for equities from corporate pensions if you look out the next several years,” said Aaron Meder, head of U.S. pension solutions for Legal and General Investment Management America. Corporations are “tired of the volatility in the stock market, so they want to de-risk their pensions,” he added.