Big Ticket | Sold for $39,000,018

Marilynn K. Yee/The New York Times 730 Park Avenue

The stealth sale of a duplex penthouse at 730 Park Avenue coveted by an elite assemblage of suitors - people with the requisite liquidity to part with nearly $40 million in cash in a heartbeat and a backup portfolio capable of impressing the building's extraordinarily selective board - was the biggest sale of the week, according to city records.

The strategically situated 12-room penthouse, No. 18/19C, with five terraces and westward views of Central Park, was never formally listed, but when word got around this spring that its owner, Joann Walker, a former Goldman Sachs banker, was in whisper-sale mode and entertaining offers in the $35 million range, a biddin g war ensued. The winning bid, at $39,000,018, belonged to Ms. Walker's own neighbor, Daniel C. Benton, the founder of Andor Capital Management, a technology hedge fund, and his wife, Anna. Clearly, they were already shareholders in good favor with the board.

In 2007, the Bentons paid $21 million for a lower-floor duplex at 730 Park, a 1929 brick beauty designed by Lafayette A. Goldstone and F. Burrall Hoffman Jr., and in 2008 Mr. Benton shut down his hedge fund and retired. But the lure of the trophy penthouse proved impossible to resist. Coincidence or not, Mr. Benton and his fund came out of retirement in 2012 just in time to make a play for No. 18/19C, where even the maid's room has a terrace with an East River view.

There are four master-of-the-universe-size bedrooms and baths, a solarium, a statement-making 37-foot-by-28-foot living room, and a glass-ceilinged greenhouse breakfast room off the kitchen; the maintenance is $13,45 1. The neighboring penthouse on the Park Avenue side belongs to Karen Lauder, the former wife of William Lauder, a grandson of Estée Lauder. A 10-room duplex, No. 15/16A, owned by the estate of Mike Wallace, of “60 Minutes” fame, entered the market in October for $20 million.

Along with a Stribling & Associates agent who preferred anonymity, Meredyth Hull Smith and Serena Boardman of Sotheby's International Realty represented the seller of the penthouse. In April, the two sold Theodore J. Forstmann's penthouse at 2 East 70th Street for $40 million, $4 million above asking price. Mr. Forstmann, a founder of the private equity firm Forstmann Little, died last year.

Ms. Smith described the penthouse at 730 Park as “a discretionary listing that honestly was just so special, it sold itself. It was a spectacular apartment that caught the resurgent uber-upper-end market perfectly.”

Big Ticket includes closed sales from the previous week, ending Wednesday.