OpenSea is a peer-to-peer marketplace for buying and selling non-fungible tokens (NFTs) on the Ethereum blockchain. It was founded in 2017 by Devin Finzer and Alex Atallah. OpenSea allows users to buy, sell, and discover rare digital items such as art, gaming items, domain names, and other collectibles. The platform has over 4 million items listed and has facilitated over $1 billion in sales. OpenSea has received funding from notable investors such as Andreessen Horowitz, Mark Cuban, and Naval Ravikant.