Decentralized exchanges offer trustless non-custodial trading, improved transparency, and inter-exchange sharing of liquidity. Despite these fundamental advantages, decentralized exchanges today account for a negligible percentage of the overall transaction volume. This lack of adoption is due to a combination of several factors: barrier to entry, performance and usability issues, susceptibility to arbitrage, and a lack of economic incentives for liquidity sharing. Hydro is a network layer protocol for high performance decentralized exchanges and marketplaces with built-in incentives for coordination. The Hydro Protocol (HOT) defines the rules for executing decentralized orders and provides the mechanism for order matching. Hydro utilizes 'Federated Liquidity Pools' (FLP) to address the issue of liquidity sharing among various decentralized exchanges.