A person, normally a broker, who has membership on a stock exchange. This means that he/she is allowed to make trades on the floor of that exchange. Most exchanges do not allow firms to be members, so the membership for a member firm formally belongs to one or more of its employees. Memberships are bought and sold at market price because most exchanges have a finite number. See also: Seat.
A broker-dealer firm in which at least one of the principal officers is allowed to trade on the floor of an exchange. To become a member, one needs to purchase a membership or a seat on the exchange, which can be very expensive. There are usually a set number of memberships to an exchange; for example, on the New York Stock Exchange, there are 1,366 seats, which may cost up to $1 million each, and which may be bought or sold to different firms. Most exchanges do not recognize member firms, only individual members; that is, they consider members to be the brokers or dealers on the floor, rather than the firms they represent.