A market activity that results from a floor broker or a brokerage firm executing trades on behalf of clients and for the broker’s own account on the same day. Dual trading can be a source of market flexibility and liquidity as it allows brokers to react quickly to changing market conditions. However, some studies argue that dual trading may hurt financial markets since dual traders earn excess profits by trading on information obtained from their client’s order flow. Such information may be exploited using strategies such as front-running and piggy-backing.