Raydium is an Automated Market Maker built for the decentralized exchange Serum on Solana.
Using Raydium swap function any SPL token can be instantly swapped into another, thanks to liquidity from two sources the first liquidity pool is Raydium’s pools and also the DEX Serum-based order book. Each transaction incurs a 0.25% transactional fee, To break this down further 88% of that fee is redeposited in the liquidity pool to incentivize liquidity providers. Now the remaining 12% is sent to RAY stake holders to reward them.
Ray token
The Ray Token is the native governance token to Raydium. It is similar to Cake or Uniswap. there is a maximum supply of 555,000,000 tokens
A.P.R.
The current apr for the 4 pools I've chosen the test Raydium are ranging for 50%-200%
USDC-BOP - 135%
RAY-SOL - 70%
USDC-STEP - 195%
USDT-RAY - 55%

Overall it's a new platform on the Solana ecosystem and the future of AMM on Solana