"Stock orders are routed via an electronic matrix to a listed, Nasdaq, or over-the-counter agent, ECN or other market participant, depending upon the security being traded, the designated market session and other factors. Freetrade and Ameritrade cannot accept requests to route orders to a specific exchange or market for execution. Ameritrade receives cash payment for routing my stock orders for execution to certain agents on specific listed, Nasdaq, and over-the-counter securities. These agents may be market makers or other market participants and may act as principal and buy, sell or hold securities for their own proprietary accounts and may make money from the "spread."