These are the 20 largest endowments and foundations in the US

They have billions of dollars under management and investments in areas as varied as coal, US Treasury bonds, and sub-Saharan Africa real estate.

No, these aren't private equity or Wall Street's biggest hedge funds.

These are nonprofit organizations serving higher education, healthcare, and the arts.

Based on second-quarter data from 2014, the finance research and data site Graypools compiled a list dominated by higher-education institutions and interspersed with healthcare funds, art-preservation societies, and financing cooperatives.

Here are the top 20 foundations and endowments in the US by gross assets, based on their regulatory filings with the IRS.

Note: Gross assets data comes from Graypools, which may "significantly inflate an organization's "size" by failing to adjust for fully-secured liabilities, such as mortgages on development real estate."