The provided text is an excerpt from the Raydium Protocol Litepaper, dated February 2021. This paper introduces Raydium, an automated market maker (AMM) built on the Solana blockchain. Raydium distinguishes itself by leveraging the central order book of the Serum decentralized exchange (DEX), aiming to provide faster trades, shared liquidity, and new yield-earning opportunities. The paper outlines the background of DeFi and existing issues on Ethereum-based AMMs, subsequently detailing Raydium's architecture, features like order books and dual reward farming, and the utility and distribution of its native RAY token.