Market Maker [MM]
A person or firm that provides liquidity, making two-sided prices (bids and offers) in the market.
A market maker or liquidity provider is a company or an individual that quotes both a buy and a sell price in a tradable asset held in inventory, hoping to make a profit on the bid–ask spread, or turn. The benefit to the firm is that it makes money from doing so; the benefit to the market is that this helps limit price variation (volatility) by setting a limited trading price range for the assets being traded.
In U.S. markets, 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 they will take a position in a particular assigned security, option, or option index.