Uniswap, founded by Hayden Adams, has long been the biggest and most popular decentralized exchange on the Ethereum network. In 2020 cryptocurrency saw an explosion of DeFi activity. Uniswap faced some steep competition and suffered 'a vampire mining attack'. Not only did Uniswap just survive, they came back with a massive airdrop for their new UNI token which took ethereum by storm and cemented their spot among the top of the DeFi world.