Perhaps mismanagement, I've bought back domains in auction that I've sold, not in the 5 figure range but some folks never update the contact info or setup auto renewal on a foreign registrar. Seems this sale was based off another token startup the developers or supporters lost interest in. "The Ivy Project started with a simple idea – that cryptocurrency and blockchain-backed tokens should make it easier for large institutions to accept payments, not more difficult." Maybe they somehow thought there was no resale value in it and decided to let it drop.