Billionaire Bob Mercer, co-CEO of the hedge fund Renaissance Technologies, has listed his New York City condo for $3.5 million.

Located at the Galleria at 117 East 57th Street, the condo apartment offers skyline views and holds two bedrooms and 2.5 bathrooms. The Galleria building is just down the street from Trump Tower.

Mercer has been one of the biggest donors of the Republican party in recent years. He donated $13 million to Ted Cruz’s Super PAC before transitioning his support to Trump after the latter secured the nomination.

Mercer’s daughter, Rebekah, has also been a major supporter of the GOP, with Trump even saying at one point this summer that, “The Mercers basically own this campaign.”

Mercer and his wife, Diane, live full-time on the North Shore of Long Island. The couple purchased the 57th Street apartment for $2.35 million in 2005.

Primarily a computer scientist, Mercer is a man of few words. He avoids the social circuit and simply cuts checks for causes and politicos he believes in.

Mercer’s net worth was estimated at $12.5 billion as of 2014.