A recent article in Bloomberg profiles David Swensen, who has overseen the Yale University endowment for 34 years and has become something of a legend—as well as the school’s highest-paid employee.

When Swensen began his tenure at Yale, the article reports, the endowment was worth $1 billion. Today, it stands at $29.4 billion. “Harvard’s stash is bigger, at $39 billion,” the article says, “but Swensen’s reputation is more than a matter of returns and asset size. He’s an intellectual leader whose once-radical ideas have become an orthodoxy.”

The article explains that Swensen convinced the “smart money” that the more appealing opportunities were presented in “esoteric hedge fund strategies and private equity rather than through buying “ordinary stocks”—a template for long-term investing now widely known as ‘the Yale model.’ “

Swensen first became a legend at Yale during when the dot com bubble burst, the article explains: “During Yale’s fiscal year ended in June 2000, when the Nasdaq hit the era’s peak, the endowment’s portfolio returned 41%. Even more impressively, over the next 12 months as stocks collapsed, Yale’s assiduously diversified portfolio returned a healthy 9.2%. Yale became an emblem of a new investing style.”

Other universities and endowments have followed Yale’s example by piling into alternative investments, the article says. According to strategist Byron Wien, Swensen “legitimized private equity as an asset class.”

The article notes that Yale’s returns have dipped in recent years, from an average of 11.8% over the past 20 years to 7.4% over the past decade. While the university isn’t complaining about these returns, the article notes that some are questioning how they’re earned–activists are raising concerns about certain endowment interests, including those in fossil fuels, in bonds issued by Puerto Rico, and in timberlands suspected of un-sustainable forestry practices.