Priciest US home purchase in history. : A billionaire hedge-fund founder purchased the most expensive U.S. home in history, eclipsing the previous record by over $100 million. Citadel founder Ken Griffin purchased a New York penthouse for roughly $238 million, The Wall Street Journal reported Wednesday. The approximately 24,000-square-foot penthouse, especially massive by New York standards, sits atop Central Park. Hedge-fund manager Barry Rosenstein held the previous record, set in 2014, when he bought a $137 million dollar home in the Hamptons. Griffin’s buy is not too far away from some of the world’s most expensive residential purchases, with most occurring in Hong Kong and Monte Carlo.