The rarest and most coveted United States stamp sold for $4.4 million via Robert A. Siegel Auction Galleries over the weekend, establishing a new record for any U.S. stamp sold at public auction.
Known as the one-cent Z-Grill, the stamp was sold by billionaire Bill Gross as part of the final auction of a multi-year sale of his entire collection — the only complete U.S. stamp collection in the world.
The previous record was held by the Inverted Jenny, which sold for $2 million in 2023.
Gross, who spent more than $100 million acquiring the collection, sold this final and most valuable selection of stamps for a total of $18 million.
The Z-Grill was acquired by Gross in 2003, during the "Greatest Stamp Swap in History," in which he traded a 24-cent Inverted Jenny Plate Block he'd purchased for $2.97 million for the one-cent Z-Grill.
Just two of the one-cent Z-Grills are known to exist, with the only other example in the collection of the New York Public Library, which received the stamp as a donation in 1925.
The record-setting one-cent Z-Grill was previously owned by former Lakers owner Jerry Buss and later investor and stamp collector Robert Zoellner.
The most expensive stamp ever sold remains a one-cent magenta from British Guiana, which sold for more than $8 million in 2021.
Will Stern is a reporter and editor for cllct.