Hedge funder Steven Schonfeld is about to close on a deal that will hand him the keys to the most expensive mansion in U.S. history, according to a report. The oceanfront property in Palm Beach, Fla., a half-mile south of President Donald Trump’s private club, Mar-a-Lago, will reportedly set the billionaire back just under a little less than $200 million in the off-market deal, the New York...