The NASD ( National Association of Securities
Dealers ) member firms that use their own capital, research, retail and/or systems resources to represent a stock and compete with each other to buy and sell the stocks or issues they represent. There are
more than 500 member firms that act as Nasdaq Market Makers. One of the major differences between The Nasdaq Stock Market and other major markets in the U.S. is Nasdaq's structure of competing Market Makers.
Each Market Maker competes for customer order flow by displaying buy and sell quotations for a guaranteed number of shares. Once an order is received, the Market Maker will immediately purchase for or sell
from its own inventory, or seek the other side of the trade until it is executed, often in a matter of seconds.