Academia continues to rebuild its fiscal position after being whacked in the financial crisis.
College and university endowments gained an average of 15.8 percent in fiscal 2014, according to preliminary data from 426 U.S. colleges and universities compiled by school association NACUBO and investment manager Commonfund. The 2014 fiscal year ran from July 1, 2013, to June 30, 2014.
The trailing three-year average annual return was 8.9 percent, according to data from 129 institutions. The numbers over five and 10 years were 11.7 percent and 7 percent, respectively. Schools are still recovering from the last recession; the average return from July 2008 to June 2009 was a loss of 18.7 percent.
The performance was driven by huge investments in so-called alternative investments, like hedge and private equity funds, venture capital and real estate.
The allocation to alternatives grew to an average of 58 percent, according to the study, including 65 percent for endowments with assets of more than $1 billion. Last year, the nonstock and bond strategies accounted for an average of 53 percent of endowment portfolios, a 1 percentage point decline from the previous year.
Venture capital produced the highest return, at 21.2 percent, followed by 18.4 percent for energy and natural resources, according to the study. Private equity returned 17 percent, distressed debt 13.5 percent and private equity real estate 11.7 percent. Hedge funds returned 9.4 percent.
Read MoreHarvard's endowment CEO: No regrets
"The greater diversification practiced by the largest endowments and their emphasis on a variety of sources of return, both public and private, tends to result in higher long-term investment performance," said the Commonfund Institute's executive director, John Griswold, in a statement.