1. President and Fellows of Harvard College
About: This refers to a portion of Harvard University's endowment fund.
The President and Fellows of Harvard College is a permanent endowment, made up of some 12,000 funds set up to support professorships, financial aid, fellowships, and student activities. It is run by Harvard University's governing body, the 12-member President and Fellows of Harvard College.
Harvard distributed about $1.5 billion in the 2012 fiscal year — a third of its operating revenue.
Gross Assets: $56.37 billion
2. Kaiser Foundation Hospitals
About: Kaiser Foundation Hospitals is a nonprofit entity under the umbrella of the healthcare giant Kaiser Permanente that offers a network of hospitals, physicians, and healthcare plans.
Kaiser Foundation Hospitals is partnered with several healthcare providers around the country, with some 10.1 million members in its network.
The gross assets represent the value of the network's 38 hospitals, 600-plus medical office buildings, and the land they sit on, said Marc Brown, manager of the media-relations department at Kaiser Permanente.
Gross Assets: $20.81 billion
3. Yale University Investment fund
About: Yale University's investment fund reported a 20-year return of 13.9% per annum, giving $20.6 billion in relative value added support to the Ivy League.
The University estimates that in the fiscal year that ended in June 2014, the endowment's invested donations under management totaled $23.9 billion.
The revenues go toward professorships, scholarships and prizes, maintenance, books, and more.
Gross Assets: $28.32 billion
4. Trustees of Princeton University
About: Princeton University's endowment fund has consistently ranked second largest among university endowments by assets under management.
In the fiscal year that ended June 30, 2014, it posted a 10-year average return of 10.5%.
The permanent endowment goes toward professorships, financial aid, and student activities, and it is managed by the Trustees of Princeton University — the Ivy's governing board.
Gross Assets: $20.81 billion
5. National Rural Utilities Cooperative Finance Corporation
About: A nonprofit, cooperative financial-services company based out of Virginia, the CFC is owned by the Electric Cooperative Network.
The nonprofit helps supplement existing loan programs to pay for the construction of utility lines, including electricity and telecommunications, especially in rural areas.
Gross Assets: $19.89 billion
6. Howard Hughes Medical Institute
About: Based out of New York, the Howard Hughes Medical Institute is the nation's largest private supporter of academic biomedical research. The organization came about after Howard Hughes, the business tycoon and aviator, surrounded himself with a group of scientists and physicians.
The group would later create a medical institution based on Hughes' principles.
The institute also supplies funds for science education and gave roughly $8 million to international research in the 2014 fiscal year.
Gross Assets: $18.12 billion
7. Trustees of Columbia University
About: Columbia University's endowment fund helps support professorships, financial aid, research, projects, centers, and more.
Twenty-six percent of assets in 2013 were allocated to global equities, 20% to private equity, 32% to absolute return strategy funds, and 18% to real assets, according to the university's Office of Alumni and Development.
According to The New York Times, in October the university posted an annual return of 17.5%, coming behind the 2014 annual return rate of Yale (20.2%) and the much smaller endowment fund of Dartmouth College (19.2%).
Gross Assets: $13.63 billion
8. Partners Healthcare Systems Inc.
About: A Boston-based hospital and patient-care network that includes medical teaching institutions, Partners Healthcare has a hosts specialty hospitals, community health centers, and academic medical centers. The organization also has a subsidiary biomedical research center.
Total operating revenue was $2.8 billion in the three months that ended in December. The network is investing most of its money market pool in US Treasurys and overnight and short-dated commercial paper and money funds.
Gross Assets: $12.6 billion
9. Harvard Management Private Equity Corporation
About: Supporting Harvard University, the corporation helps fund Harvard's endowment, and it is under the care of Harvard Management Company.
The corporation "invests funds for the benefit of the President and Fellows of Harvard College, a related ... organization" according to its 990 filing.
Gross Assets: $11.14 billion
10. Ford Foundation
About: A New York-based organization that focuses on social change, the organization was created by Edsel and Henry Ford, the creator of Ford Motor Company.
The organization has branched out into human-welfare projects around the world.
Its portfolio is made up of private equity, venture capital, growth equity, distressed investments, and hedge funds. The hedge fund portfolio alone makes up 25% of the foundation's endowment.
As of 2013, the foundation invested 51% of its funds in alternative investments and 20% in private equity and venture capital.
Gross Assets: $10.98 billion
11. Emory University
About: In the fiscal year that ended in August 2014, Emory University's endowment generated returns of 18.2% — adding close to $1 billion in value to its portfolio.
According to university's investing team, the portfolio has more than $7 billion in diversified investments that is overseen by both Emory University and Emory Healthcare.
It contributes funding to the university's scholarships and medical research.
Gross Assets: $10.38 billion
12. Cleveland Clinic Foundation
About: Based out of Ohio, the Cleveland Clinic Foundation helps fund the nonprofit academic medical center Cleveland Clinic.
In 2014, the foundation's endowment consisted of 261 donor-restricted funds, meaning funds have specific purposes, for example, to finance education, research, or healthcare.
The foundation expects an average return rate of 7.5% annually.
Contributions and grants increased nearly 13% from 2012 to 2013, according to the foundation's 990 filing — at $897.9 million. Program service revenue accounted for most of the foundation's gross assets, with $3.2 billion.
Gross Assets: $10.22 billion
12. Duke University
About: The "Ivy of the South," Duke University's endowment is made up of more than 4,400 individual funds, totaling about $7 billion, according to its website.
Like most university endowments, Duke delivers funding to scholarships, fellowships, professorships, programs, research, and more. Thirty-two percent of funds are unrestricted and can be used however the university deems fit.
The endowment grew from $3.2 billion in size in 2000 to $7 billion in 2014. For 2014, the university also posted a 10-year annualized return rate of 10.8%.
Gross Assets: $10.2 billion
14. Northwestern University
About: The university endowment fund has allocated assets largely to venture capital and global buyout funds (20%), and long-short equities (18%).
The 10-year annualized total return as of August 2014 clocked in at 9.6%. The fund grew from $956 million in 1992 to about $9.7 billion by August 2014.
Gross Assets: $9.84 billion
15. University of Chicago
About: The University of Chicago's endowment had a market value of $7.55 billion at the end of the 2014 fiscal year, according to its website.
In the same year, returns from the endowment's main portfolio — which accounts for 96% of the endowment — generated $893 million, with annualized returns from the past 20 years clocking in at 11.2%.
The endowment is invested in an array of assets including global stocks and bonds, natural resources, private equity, absolute return strategies, and tail hedging strategies.
Gross Assets: $9.62 billion
16. University of Notre Dame du Lac
About: The Catholic school has been increasingly focused on diversifying its portfolio because of geopolitical instability and US labor-market trends during the fiscal year that ended in June 2014.
The market value of the pool in 2014 increased to $9.81 billion from $8.32 billion — meaning a 19.7% net of investment management fees.
The majority of assets went into public and private equities, with the returns helping fund $300 million, or roughly 25%, of Notre Dame's activities that year, according to the university's Office of the Controller.
Gross Assets: $9.33 billion
17. J. Paul Getty Trust
About: A cultural and philanthropic organization that aims to cultivate interest in the arts and civil society, the Getty is also considered one of the world's wealthiest art societies.
The organization collects, conserves, and curates artwork and gardens while educating people about the works.
Gross Assets: $8.77 billion
18. Mayo Clinic
About: Consistently ranked among the best hospitals and teaching medical centers in the US, Mayo Clinic is a nonprofit medical-research group based out of Minnesota.
The clinic has several satellites around the country, and it is known for specializing in hard-to-treat cases.
Its endowment, made up of roughly 1,000 individual funds, helps provide operating expenses for research, educational programs, and more. In 2010, Mayo Clinic estimated that its endowment amounted to $1.8 billion.
Five-year annualized returns in 2010 clocked in at 6.9%.
Gross Assets: $8.53 billion
19. Memorial Sloan Kettering Cancer Center
About: The center, which focuses on research for cancer treatment, rehabilitation, and prevention, is known to make "niche plays" within its portfolio, according to Dawn Lim, a writer for Foundation and Endowment Intelligence, an online and print magazine.
These plays also may not yield immediate returns but produce payoffs in the future. According to Lim, Memorial Sloan-Kettering has made investments in sub-Saharan Africa to capture its commercial-real-estate sector.
In 2012, the fund delivered 11% to 15% from its $3.5 billion portfolio.
Gross Assets: $8.48 billion
20. Shriners Hospitals for Children
About: A network of roughly 22 nonprofits across North America, Shriners is headquartered in Tampa, Florida.
After the 2008 financial crisis, the charitable organization was nearly forced to close six of its hospitals after seeing its endowment sapped, but it eventually decided to tap into funds from insurance companies, according to The Tampa Tribune.
The endowment is made up of charitable gifts, marketable securities, and real estate and mineral interests, as well as other investments including equity and fixed-income securities.
The expected average rate of return has been posted at 7.25% annually, as of 2012.
Gross Assets: $8.3 billion