Devin Finzer and Alex Atallah founded OpenSea in December 2017, aiming to build a general marketplace for NFTs inspired by early projects like CryptoKitties. This provided a simple place to list and trade “crypto goods,” which helped normalize the idea of virtual property having a market price.
In 2018, OpenSea entered Y Combinator, a startup accelerator that helped it refine its product and growth plan. The backing signaled that NFT marketplaces could be real businesses, not just side projects for crypto hobbyists.
OpenSea announced a $2.1 million strategic investment in November 2019 from partners including Animoca Brands and gumi Cryptos. This funding supported platform development and partnerships at a time when NFT trading was still a niche activity.
Rarible emerged as a competing NFT marketplace in 2020, emphasizing easier “minting” (creating an NFT) for creators. Its growth helped shift NFTs from a small collector market toward a broader creator economy where more people could publish and sell digital items.
On July 15, 2020, Rarible introduced the RARI token, describing it as a governance token for community voting and marketplace incentives. This connected NFT marketplaces to “token incentives,” where users could be rewarded for trading activity—an approach later copied by other competitors.
In March 2021, OpenSea announced a $23 million funding round led by Andreessen Horowitz, with participation from well-known angels and founders. The round reflected rising investor confidence that NFT marketplaces could become major consumer platforms.
In June 2021, Rarible announced a $14.2 million Series A and said it planned expansion onto Flow, a blockchain aimed at cheaper and more user-friendly NFT transactions. This reflected an “expansion phase” where marketplaces tried to reduce fees and reach new audiences by going multi-chain.
In July 2021, OpenSea announced a $100 million Series B led by Andreessen Horowitz at a $1.5 billion valuation. The funding helped OpenSea scale during rapidly increasing demand, and it also raised the competitive stakes for other marketplaces.
By August 2021, OpenSea recorded about $3.4 billion in transactions for the month, reflecting a major surge in NFT speculation and collecting. This boom pushed marketplaces to expand features like auctions, fixed-price listings, and multi-collection discovery to handle mass adoption.
Magic Eden launched in September 2021 as a marketplace focused on Solana, a blockchain known for fast and low-cost transactions. Its growth showed that major NFT trading activity could shift to other chains, pressuring Ethereum-based marketplaces to broaden their offerings.
In January 2022, OpenSea announced a $300 million Series C round that valued the company at about $13.3 billion. The round marked the high point of the 2018–2022 marketplace expansion era, when NFT marketplaces scaled quickly and attracted major venture funding as NFT trading volumes peaked.
LooksRare launched on January 10, 2022 and promoted an airdrop to eligible OpenSea users, using token rewards to pull traders to a new marketplace. This highlighted a turning point: marketplaces were no longer competing only on user experience, but also on financial incentives and fee models.
NFT marketplaces expansion: OpenSea, Rarible and major marketplaces (2018–2022)