OpenSea
OpenSea, founded in December 2017 by Devin Finzer and Alex Atallah in New York, pioneered the market for NFT trading and remains a leading peer-to-peer marketplace for digital collectibles. Its platform supports Ethereum, Polygon, Base and other EVM chains, offering listing, bidding, aggregation, drops and creator analytics with wallet-based settlement and royalty controls. Now headquartered in Miami with hubs in New York and San Francisco, OpenSea served as the primary venue through the 2021 NFT cycle and has since expanded to token swaps, studio tools and mobile. Backed by Andreessen Horowitz and Paradigm at a $13.3B peak valuation, the company emphasizes marketplace reliability, trust and safety, and creator tooling. Expect a marketplace-driven culture that values curation, product iteration and maintaining reliable trading infrastructure through volatile collector demand.