A quick mobile search for “NFT” turns up hundreds of thumb-stopping headlines.

A highlight of a LeBron James dunk sold for $208,000. The artist Grimes garnered nearly $6 million for a series of digital art. Jack Dorsey auctioned the first-ever tweet for $2.9 million.

NFTs are turning every type of art — from fine art to music to anime — into an asset that can be bought and resold for big returns. That’s particularly exciting for the reseller, but what about fans who just want to dip their ...