A person or firm who buys and sells securities for their own account, whether through a broker or otherwise. A dealer acts as a principal in trading for its own account, as opposed to a broker who acts as an agent who executes orders on behalf of its clients. Dealers are important figures — they make markets in securities, underwrite securities, provide investment services to investors, and provide the bid-and-ask quotes visible when you look up the price of a security in the over-the-counter market. Dealers also help to create liquidity in the markets and boost long-term growth.