While bitcoin and other cryptocurrencies have become increasingly popular, so have crypto collectibles.

According to CNBC, Twitter CEO Jack Dorsey is selling the very first tweet as a “non-fungible token.”  The tweet for sale is Dorsey’s first tweet in 2006 which says, “just setting up my twttr”

He shared a link this past Friday afternoon for people to bid on the tweet. The current bid as at more than $2.5 million.