OpenSea is an online marketplace for non-fungible tokens. It was founded by Devin Finzer and Alex Atallah in New York on December 20, 2017.
Users can generate NFTs for free on OpenSea and offer them for direct purchase or auction. OpenSea is based on the Ethereum ERC-721 standard and Polygon (a layer-2 scaling solution for Ethereum).
After a 2018 pre-seed round by Y Combinator, OpenSea raised $2.1 million in venture capital (including from Animoca Brands) in November 2019. In March 2021, OpenSea raised an additional $23 million in venture capital (including. A16z Crypto/Andreessen Horowitz, among others). In July 2021, OpenSea announced another investment round of $100 million at a valuation of $1.5 billion by a16z.
In February 2021, revenues were the equivalent of $95 million, in March the equivalent of $147 million, and in September $2.75 billion.
In September 2021, OpenSea released an app for Android and iOS. The app allowed browsing the market place, but not buying or selling NFTs. The same month, OpenSea admitted that an employee engaged in insider trading. OpenSea's Head of Product hoarded NFTs just before they were featured in the homepage.
In January 2022, OpenSea raised $300 million in new venture capital (Paradigm and Coatue Management), valuing it at $13.3 billion.