On Dec. 23, while many Americans were on holiday, the cryptocurrency exchange Crypto.com made an unexpected announcement: the Singapore-based company was inviting users in the US to “trade their own prediction” on sports events, including who would win the Super Bowl.Alongside the chance to buy and sell memecoins and NFTs, Crypto.com added markets for “yes” or “no” positions on the outcome of the NFL playoffs and college football bowl games. Technically, these are “swaps” contracts: For every “y...