Sell side are selling liquidity, they're like car dealers who stand ready to buy or sell any financial instrument with buy side firms. As well as the buy side f

Sell side are selling liquidity, they're like car dealers who stand ready to buy or sell any financial instrument with buy side firms. As well as the buy side firms listed by tomp above there are also what we call "real money": pension and insurance funds. Unlike hedge funds they are regulated and have to run long only strategies. Can't have pension funds blowing up LTCM style.