In a modern financial system, Swensen reasoned, diversification should mean more than simply holding a broad mix of U.S. bonds and equities: Assets such as foreign equities, real estate, private equity, oil, gas, and timber all offered ways to add equity-type returns while diversifying risk substantially. Then there was another kind of asset that took Swensen’s fancy. He called it “absolute return,” and over the next years the term entered the investment lexicon. It was a synonym for hedge funds.