A trader who buys exchange services from a sell-side trader (s). Examples of buy-side traders are individual investors and institutional investors (portfolio managers, mutual funds, pension funds, etc) as well as borrowers, hedgers, gamblers, etc. In other words, buy-side traders resort to the markets for many reasons including investment, liquidation, borrowing, hedging, asset exchange, gambling, etc. They usually buy exchange or liquidity services by taking or seeking to take positions in securities and contracts.