Jack Dorsey, CEO of Twitter, speaks to students during a town hall at the Indian Institute of Technology (IIT) in New Delhi, India on November 12, 2018.

Anushree Fadnavis | Reuters

The first tweet from Twitter CEO Jack Dorsey, which was put up for sale as a non-fungible token, went on sale Monday for 1,630.58 ether, a cryptocurrency. This equates to approximately $ 2.9 million based on the price of the ether at the time of sale.

The tweet labeled “Just Setup My Twttr” was first posted on March 21, 2006. It went up for sale on March 6th as an NFT. Until March 9th, the highest bid was from Sina Estavi, CEO of Bridge Oracle. Estavi won the auction, and although his bid was worth approximately $ 2.5 million, it was placed.

Ownership of these assets is recorded on a blockchain – a digital ledger similar to those that support Bitcoin and other cryptocurrencies. But one person cannot swap one NFT for another like dollars or other assets would. Each NFT is unique and acts as a collector’s item that cannot be duplicated, which inherently makes them rare.

Dorsey said he will convert the proceeds into bitcoin and then donate it to Give Directly’s Africa Response Fund.

CNBC’s Jessica Bursztynsky contributed to this report.