A market maker or liquidity provider is a company or an individual that quotes both a buy and a sell price in a financial instrument or commodity held in inventory, hoping to make a profit on the bid-offer spread, or turn. The U.S. Securities and Exchange Commission defines a "market maker" as a firm that stands ready to buy and sell stock on a regular and continuous basis at a publicly quoted price.A Designated Primary Market Maker (DPM) is a specialized market maker approved by an exchange to guarantee that he or she will take the position in a particular assigned security, option or option index.