Sports fans, get out your digital wallets. If you’ve been on the internet recently, you’ve probably seen references to NFTs, or non-fungible tokens.
 An NFT, in simple terms, is a unique digital file on the blockchain, a digital ledger. This digital file could be a photo, video, audio or anything else online. Think of NFTs as virtual collectibles, and they have created a whole new market of sports memorabilia for collectors to buy and sell. 
 These are the most expensive sports NFTs for sale.