It’s no secret that the private equity industry wants to get into the personal retirement business. The investment giant BlackRock is pledging to “open up private markets to millions of everyday investors.”

BlackRock president Larry Fink claims the company wants to give ordinary people access to risky assets and high returns. Risky assets? Yes. High returns? Well, let’s ask the sophisticated investors at the nation’s largest university endowment funds how that worked out.

Pitchbook is out with the latest returns to university endowments from alternative investments in private equity buyout funds, private credit, real estate and real assets. These endowments are now among the largest investors in these assets. The top 50 university endowments in the US have a total of $806.2 billion invested in these private assets.

The University of California has the largest university endowment at close to $180 billion. Twenty percent ($34.2 billion) of the endowment’s funds are invested in these alternative investments. Harvard University, with the fourth largest endowment, has nearly 40 percent invested in these alternatives.

Investments in these private assets are illiquid – meaning they don’t trade on a public market, can’t easily be sold, and tie up the endowments’ funds for years at a time. This contrasts with investments in publicly traded stocks and bonds which can be sold at any time. In return for taking on the extra risk of investing in illiquid assets, investors expect higher returns – typically a premium of about 3 percent over gains in the stock market.

So, how did the endowments fare? Pitchbook reports that the 50 largest university endowments saw an annual return of 8.3 percent over the past 10 years. And how did a plain vanilla 60-40 Vanguard mutual fund (60 percent stocks, 40 percent bonds) do? It returned 8.38 percent over the same period without the added risk of speculative investments in risky private assets.

Let that sink in. Endowment funds got no extra payoff for investing in private equity funds or other private assets.

The lesson? US endowment funds could have made the same return by joining with millions of ordinary people and investing in a plain vanilla mutual fund.