Sealed-bid auction
Bids are submitted privately and revealed only at close. Each bidder picks their max number once, blind to what others bid. Highest sealed bid wins.
Why it’s used
Sealed-bid eliminates the strategic back-and-forth of English auctions. It’s preferred by brokered premium domains where the seller doesn’t want bidders pacing each other up by $5 increments over a 7-day window.
Trade-off
Winners often overpay relative to second place (the ‘winner’s curse’) unless the auction is second-price.