Reef is new, unaudited software. Pools can have little or no liquidity, and quotes can move between the time you type an amount and the time you confirm. Only trade what you can afford to lose, and check the receiving amount before you sign.

Providing liquidity carries risk. If the price of the two tokens moves apart, you can end up with less value than if you had just held them (impermanent loss). Fees earned may not offset this. Reef takes no cut beyond the pool fee unless the protocol fee switch is later turned on by governance.