A trader who provides exchange services to buy-side traders (or investors). Sell-side traders either trade on behalf of their clients (hence are known as brokers) or for their own account and risk (hence are called dealers) in a securities transaction. Dealers and brokers help buy-side traders trade by standing ready to assume the counterpart side of a trade. Other traders deal for their own and broker deals for others (therefore, they are referred to as broker-dealers or dual traders). On the sell-side, there are also inter-dealer brokers who facilitate inter-dealer trades.

Sell-side traders execute orders and route them to the best possible trades.