Raydium is an automated market maker (AMM) and liquidity provider built on the Solana blockchain for the Serum decentralized exchange (DEX). Unlike any other AMMs, Raydium provides on-chain liquidity to a central limit orderbook meaning that funds deposited into Raydium are converted into limit orders which sit on Serum’s orderbooks. This gives Raydium LPs access to all of Serum’s order flow as well as their existing liquidity.
RAY is the native utility token used for:
Staking to earn protocol fees
Staking to receive IDO allocations
Governance votes on protocol decisions

Trade & Swap
Trade
Raydium is able to offer a powerful trading experience similar to that of a centralized exchange (CEX) thanks to integration with Serum. If you've ever been annoyed by the total absence of an order book, charting, or reliable limit orders on other DEXs, we think you're going to love trading on Raydium.

Swap
If you prefer a quick and easy "Swap" option, we've still got you covered! Any SPL token can be quickly exchanged for another with RaydiumSwap.
Raydium’s Best Price Swaps determines whether swapping within a liquidity pool or through the Serum order book will provide the best price for the user, and executes accordingly.

Liquidity
Raydium's liquidity comes both from its own liquidity pools, as well as from the wider Serum order book shared by all Serum users. This means more liquidity and less slippage for Raydium traders.
When you make a trade or swap on Raydium the transaction is charged a 0.25% fee:

0.22% is redeposited into the liquidity pool and acts as a reward for liquidity providers.

0.03% is sent to the staking pool and acts as a reward for those staking their RAY tokens