Billionaire Ken Griffin, the richest person in Illinois, reportedly shelled out $500 million for only two paintings previously owned by David Geffen’s foundation. It is believed to be the biggest private art deals ever.

At least the two pieces are by masters. According to the Chicago Tribune, one piece was Interchange (1955) by Willem de Kooning and the other was Jackson Pollack’s Number 17A (1948). The de Kooning piece was $300 million, while the Pollack was $200 million.

The prices far exceed the auction records for both Abstract Expressionist artists. According to Artnet, the record for de Kooning was set in 2013 by his Untitled VIII, which went for $32 million. Pollack’s Number 19 sold for $58.3 million in 2013.

The two pieces were on display at the Art Institute of Chicago in September. Geffen is a trustee of the museum.

Before Griffin’s deal with Geffen, the previous high mark for a private sale was set last year when Swiss collector Rudolf Staechelin sold Paul Gauguin’s When Will You Marry? for $300 million to the Qatar Museums.

Griffin is estimated to be worth $5.6 billion by Bloomberg and has an art collection valued at $2.3 billion. His wealth comes from the hedge fund Citadel Wellington.