The Simons Foundation is a private foundation founded by left-leaning Renaissance Technologies hedge fund founder James Simons and his wife, Marilyn. The Foundation funds research in four broad areas: mathematics and physical sciences, life sciences, autism research, and “Outreach & Education.” The Foundation conducts its own research through the Flatiron Institute, but is partnered with a long-list of organizations, many of which tend to lean politically left-of-center.  With an endowment of over $2 billion, the Simons Foundation is among the top 40 wealthiest foundations in the country. 
James Simons founded the Simons Foundation in the 1990s along with his wife, Marilyn. The Simons Foundation Autism Research Initiative was founded in 2003 to better understand autism disorders and make progress toward a cure. 
In 2016, the Foundation made a major investment in computational science by opening its own research center, the Flatiron Institute. Governor Andrew Cuomo (D-N.Y.) joined Jim and Marilyn Simons to dedicate the new institute. 
James Simons, founder of the hedge fund firm Renaissance Technologies, is a mainstay on Forbes annual listing of the richest people in the world and a well-known supporter of liberal political causes.  The Foundation reflects his values and plays a key role in his charitable giving. In 2012, the Foundation directed a $60 million grant to the University of California, Berkeley.  In 2008, then-Gov. Eliot Spitzer (D-N.Y.) announced the Foundation’s gift of $60 million to Stony Brook University, the largest gift to a public university in the history of the state. 
Toward the end of President Barack Obama’s administration, Jim and Marilyn Simons attended a fundraising dinner at the White House. They gave $340,000 to the Obama Foundation in 2014 and $330,000 in 2015. Simons is reliably one of the Democratic Party’s heftiest donors. 
In November, 2017, The Guardian reported that James Simons had stashed more than $8 billion in a tax-free offshore account. He was one of the many people named in the so-called Paradise Papers. Simons’s alleged tax sheltering arrangements existed while he was one of the Democratic Party’s heftiest donors, responsible for $27 million during the 2016 election. 
In 2015, the New York Times reported that the IRS was reviewing whether Simons’s hedge fund, Renaissance Technologies, had withheld $6.8 billion in taxes.  Senator John McCain (R-Arizona) alleged, “Renaissance Technologies was able to avoid paying more than $6 billion in taxes by disguising its day-to-day stock trades as long term investments,” in his opening statement during a 2014 Senate investigation. 
The Lord Jim Trust was dissolved in 2010. Lawyers told Simons donating the money to charity was the best way to avoid taxes. The pile was split up among the charities started by Simons and each of his three children, including the Simons Foundation. 
During the Obama administration, Opensecrets.org showed a correlation between the President’s legislative priorities and the pet causes of his super-PAC’s largest donors. Simons donated $5 million to Priorities USA Action in 2012, and Obama signed a $1.3 billion bill for autism research in 2014. 
The Simons Foundation’s principal grantmaking efforts fund a number of scientific research programs through various universities.
The Simons Foundation funds two online publications, Quanta Magazine and Spectrum. Despite the fact that Spectrum considers itself the “leading source of news and expert opinion on autism research,” the site has engaged in advocacy against Republican policies.