The term broker dealer actually refers to the two capacities in which a firm may act when executing a transaction. When a firm is acting as a broker, it is acting as the customer’s agent and is merely executing the customer’s order for a fee known as a commission. The role of the broker is simply to find someone willing to buy the investor’s securities if the customer is selling or to find someone willing to sell them the securities if they are buyers. The firm acts as a dealer when it participates in the transaction by taking the opposite side of the trade. For example, the firm may fill a customer’s buy order by selling the securities to the customer from the firm’s own account or the dealer may fill the customer’s sell order by buying the securities for their own account. A brokerage firm is always acting as a dealer or in a principal capacity when it is making markets over the counter.