Chris Chapman used to own one of the most valuable commodities in the crypto world: a unique digital image of a spiky-haired ape dressed in a spacesuit.

Chapman bought the non-fungible token last year, as a widely hyped series of digital collectibles called the Bored Ape Yacht Club became a phenomenon. In December, he listed his Bored Ape for sale on OpenSea, the largest NFT marketplace, setting the price at about $US1 million. Two months later, as he got ready to take his daughters to the zoo, OpenSea sent him a notification: the ape had been sold for roughly $US300,000 ($415,000).