OpenSea
also invests · investor profileUnicorn · $13.3BYC W18New York City, US · Founded 2017 · 75 employees · 28 known investors
Courtyard.io is a marketplace and tokenization service that enables users to own and trade physical collectible cards on the blockchain, with options to store them vaulted, sell them, or redeem the NFT for physical delivery.
Also known as Ozone · Ozone Networks, Inc.
Founders & leadership· Y Combinator alumni (W18)
OpenSea was founded in 2017 by Devin Finzer and Alex Atallah.
Investors · 28
Valuation · disclosed
Disclosed eventsSource: SEC prospectus filings, and round valuations the company or its investors disclosed — follow each entry's link for the claim.
Company profile
researched Aug 2026OpenSea operates a peer-to-peer marketplace where users discover, buy, sell and trade onchain assets. The platform covers NFTs across categories including gaming, art, PFPs, memberships, music, photography and tokenized physical items, alongside fungible token trading, cross-chain swaps and perpetuals. Its website surfaces featured and trending collections, live and upcoming mint drops, floor prices, token fully-diluted valuations and top movers, plus introductory educational content on NFTs, minting and Web3.
The company describes itself as having pioneered the first non-custodial marketplace for digital assets and as having evolved into a venue for the broader onchain economy, spanning tokens, digital assets and physical assets. An upgraded platform, OS2, launched in May 2025 with support for 19 blockchains and added a Voyages rewards system and a $SEA governance token. A mobile app, published by Ozone Networks, Inc., lets users connect multiple wallets, track a combined portfolio across 24+ blockchains, and trade tokens and NFTs across chains including Ethereum, Solana, Base, Polygon, Arbitrum, Optimism, Avalanche, ApeChain, Flow, Ronin, Zora, Sei, HyperEVM, Monad, Berachain, Blast, Unichain, Shape, Somnia, Soneium, GUNZ, B3, INK and MegaETH.
OpenSea also runs support and documentation resources covering account management, buying and selling NFTs, token swaps, collection and drop creation, mobile, perpetuals, content moderation, user safety and developer tooling, and publishes a blog/newsletter ("Currents") covering web3 news.
Founding story
Sources give differing accounts of the founding team: one describes OpenSea as founded in 2017 by Alex Atallah and Devin Finzer to build a decentralized marketplace for digital assets using blockchain technology, while the same site's FAQ names Devin Finzer (Founder/CEO) and Chris Maddern (Co-Founder). Devin Finzer previously worked as a software engineer at Google and Pinterest and sold a prior company to Credit Karma. The company took part in Y Combinator's Winter 2018 batch.
Business model
Marketplace model: OpenSea operates a non-custodial, peer-to-peer trading venue connecting buyers, sellers and creators of NFTs and tokens across multiple blockchains, with creator tools for launching collections and drops. The sources do not detail fee structures beyond references to low fees and gas-free options on Polygon.
Not specified in the sources; third-party commentary references low fees and gas-free trading options on Polygon, but no fee or revenue figures are given.
Traction
Third-party data indicates $425.0M raised across four rounds, a team size listed at 75 by Y Combinator and an employee range of 201-500 by another directory, a mobile app with 5M+ Google Play downloads and a 4.2 rating from about 24.9K reviews, and a reported 71.5%+ share of Ethereum NFT trading volume in 2025. The company stated its transaction volume increased over 600x in 2021. It has also made 13 startup investments, including seed rounds in Daylight and Demox Labs.
Latest developments
As of August 2026 the mobile app was last updated on 2026-08-20 and the company's blog published items including an OpenSea Mobile contest (August 2026), a weekly web3 news digest, and U.S. crypto-ownership data (August 2026). The help center documents perpetuals trading and token swapping alongside NFT features, indicating an expanded product scope beyond NFTs.
▸Full profile — market position, technology, go-to-market, geography, history, risks & controversies
Market position
Described by third-party sources as the largest peer-to-peer NFT marketplace by volume, with over 71.5% of Ethereum NFT trading volume in 2025 and deep liquidity, while facing competition from platforms such as Blur and Magic Eden.
Cited differentiators include breadth of blockchain support (19 chains on OS2; 24+ for portfolio tracking), a non-custodial architecture that works with users' existing wallets, coverage of many asset categories including tokenized physical items, cross-chain swaps in a single app, a rewards program tied to a governance token, and network liquidity from being the largest NFT marketplace by volume.
Technology
Blockchain-based, non-custodial infrastructure allowing users to connect their own wallets. Supports minting, listing and trading of NFTs, token swaps including cross-chain swaps, perpetuals trading, and portfolio aggregation across 24+ chains. A rarity-ranking protocol was implemented in 2022, and the OS2 platform adds multi-chain support, a rewards system and a governance token.
Go-to-market
Self-serve web platform and mobile app distributed through app stores, supported by curated collection and drop features, educational "NFT 101" content, a help center, a newsletter and blog, creator grant programs, and integrations/partnerships reported with PayPal and Vend.
Creators, collectors, gamers, traders and investors in digital assets, ranging from first-time NFT buyers to active multi-chain token traders; described by a third-party source as serving millions of users.
Geography
Headquartered in New York City, NY, USA per company directories; the mobile app developer, Ozone Networks, Inc., lists an address in Miami, Florida. The platform is accessible globally and supports assets across many blockchains.
History
Founded in 2017 and part of Y Combinator's Winter 2018 batch, OpenSea raised seed funding in May 2018, a Series A in March 2021, a Series B in July 2021, and a $300M Series C announced January 4, 2022 at a $13.3 billion post-money valuation led by Paradigm and Coatue. Following the Series C, the company hired Shiva Rajaraman (formerly Meta) as VP of Product and said it planned to expand customer support and trust and safety teams beyond 60 people and launch a creator grant program. In 2022 it added an NFT rarity-ranking protocol and launched a marketplace on Avalanche. In May 2025 it launched the OS2 platform with 19-chain support, the Voyages rewards system and the $SEA token, and has since extended into token trading, cross-chain swaps and perpetuals.
Risks & controversies
User reviews on Google Play report access being gated behind a waitlist for a previously active account, an inability to export the in-app wallet, and transaction errors affecting swapping, minting, selling and buying. The app is rated Teen with a "Diverse Content: Discretion Advised" notice. Third-party commentary notes competition from Blur and Magic Eden. Sources also conflict on basic company facts such as co-founder identity and employee count.
Compiled by commissioned research from 8 cited public sources — announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed — not independently audited.
Founder mafia
The OpenSea mafia →6 people who came through OpenSea went on to found or lead other companies.
Competitors · 10
by search overlap
Companies competing with OpenSea for the same Google search keywords, organic and paid, via search-intersection analysis.
Acquisitions · 1
Early investors' stakes continue via these dealsDharma Labs operates an Ethereum wallet that connects US bank accounts to decentralized exchanges, allowing users to purchase cryptocurrency tokens and access DeFi yield opportunities from a mobile app.
Timeline · 8
launches, deals, and filingsUpgraded OS2 platform launched supporting 19 blockchains and introducing the Voyages rewards system and the $SEA governance token.
Integrations reported to facilitate fiat payments and retail NFT sales.
Round led by Hack VC with numerous co-investors.
$5M source ↗
Round led by Framework Ventures and Chapter One.
$3M source ↗
Paradigm and Coatue led a $300 million Series C round with participation from new and existing investors. Stated uses: accelerating product development, improving customer support and safety, community investment via a grant program, and team growth.
$300M source ↗
OpenSea announced Shiva Rajaraman, previously VP of Commerce at Meta and formerly at YouTube, Spotify and WeWork, as its new VP of Product.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
In the news
OpenSea founder pivoted to AI — and wonprotos.com · Aug 2026▸Research sources · 8
primary sources listed
- OpenSeaopensea.io · web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does OpenSea do?
- OpenSea is a multi-chain, non-custodial marketplace for trading NFTs and crypto tokens across major blockchains.
- Who founded OpenSea?
- OpenSea was founded by Devin Finzer, Alex Atallah in 2017.
- Who are OpenSea's investors?
- OpenSea's investors include 1confirmation, A.Capital Ventures, a16z crypto, Andreessen Horowitz, Balaji Srinivasan, Blockchain Capital, Coatue Management, Coinbase Ventures and 20 more.
- Where is OpenSea headquartered?
- OpenSea is headquartered in New York City, US.