An article in The Wall Street Journal reports a new study which shows that while many nonprofits “promote great causes, few are great at managing money.”

The study, which evaluated the investment returns of a large sample of nonprofits for the period from 2009 through 2016, found that they returned an average of 6.7% annually, compared to 12.2% for U.S. stocks, 10.5% for a 60/40 mix of stocks and bonds, and 8% for U.S. Treasuries.

The study’s authors–finance professors Sandeep Dahiya (Georgetown University) and David Yermack (New York University)—sifted through IRS data to estimate returns on the investment funds of early 29,000 nonprofits organizations with a total of $662 billion assets. According to the article, this gave a broader measure of investment returns than earlier studies by academic and industry researchers because it “used more selective samples that might not have been representative of typical performance among all nonprofits, large and small.”

The study also revealed that the risk-adjusted return of the 20 largest university endowments only beat the U.S. stock market by a “microscopic” 0.001% annually and, among them, 40% underperformed.

Matthew Hamill, a spokesman for the National Association of College and University Business Officers (which has studied educational endowment investment returns since the 1970s) said that the new study “comes to quite different conclusions than other organizations have found, including our own annual studies.”

The findings, the article concludes, are a “reminder of just how rare the smart money is.”