In this case, a person successfully sold their Pudgy Penguin NFT for 8.69 ETH a year ago ($27,500 at the time of sale). Those particular NFTs have been having a comeback lately, and so the collector bought the same NFT back — this time for 20 ETH ($31,500 at the time of sale). However, an old listing from their previous ownership was still active, and someone was able to snap up the NFT from them for only 9.89 ETH ($15,600) within minutes.
The collector's near-instantaneous $20,000 loss has a happy ending for them, though — the person who bought the NFT was willing to reverse the trade.