I found a leak:

The Mercer Family Foundation is the vehicle for right-wing hedge fund billionaire Robert Mercer to influence politics through contributions to like-minded advocacy groups. Robert Mercer and his foundation rose to prominence as a political kingmaker in the 2016 election due to his early support of Donald Trump's candidacy for president. In total it is estimated that Robert Mercer has contributed $100 million to right-wing groups, most of it going through the Mercer Family Foundation, which is directed by his daughter Rebekah Mercer.[1] Some of the right-wing groups backed by the Mercer Family Foundation include the Heritage Foundation and the Federalist Society. The foundation was established in 2004.[2]

The Mercer Family has close ties to current and former Trump administration advisors, such as Stephen Bannon, and Kellyanne Conway, and the Foundation has donated to causes and candidates tied to these advisors.[3]"

Paradise Papers Leaks

In November 2017, the Paradise Papers data leak disclosed information about the hidden wealth of some of the richest and most famous individuals across the world, including Robert Mercer. The Paradise Papers demonstrated that much of the assets held under the Mercer Family Foundation are kept in offshore accounts and shell corporations. The foundation used what was termed “feeder funds”— or offshoots of the main hedge fund owned by Mercer: Renaissance Technologies. These feeder funds are registered to Bermuda law firm Appleby, one of the main sources of the Paradise Papers. The Mercers then sold off their Bermuda investments in the feeder funds and put the proceeds in the Mercer Family Foundation. This avoided up to 39% in U.S. taxes that is normally levied on nonprofits funded by investments financed through debt. According to a financial advisor speaking to the Guardian “this is simple, but ingenious. You take retirement plans or foundations, you invest them in a hedge fund, and even if the value rises 100 percent, you can sell off the investments with no tax consequences.”[4]

Connections to Stephen Bannon

Robert Mercer and his daughter Rebekah have used the Mercer Family Foundation to funnel money to their ally Stephen Bannon, former Editor of Breitbart News Network and Chief Strategist for President Trump. In the early years of Bannon's leadership at Breitbart, the Mercer Family invested heavily in the struggling news outlet. It is reported they injected over $10 million in the company, which allowed Bannon to build it into one of the most recognizable right-wing media outlets in the country.[1] The Mercer Family Foundation also bankrolled Bannon's behind the scenes effort to produce the book "Clinton Cash: The Untold Story of How and Why Foreign Governments and Businesses Helped Make Bill and Hillary Rich." The book was authored by Peter Schweizer, president of the Government Accountability Institute and a former William J. Casey Research Fellow at Stanford University's Hoover Institution. The book included many dubious claims about the Clintons, including the charge that mining executives contributed to the Clinton Foundation to assist their lucrative sale of a uranium company to a Russian state energy agency.[5]

https://www.sourcewatch.org/index.php?title=Mercer_Family_Foundation