Market makers are financial firms or individuals that help facilitate trading in financial markets by providing liquidity. They do this by continuously buying and selling securities, such as stocks or bonds, at publicly quoted prices. By doing so, they ensure that there are always buyers and sellers available, which helps to stabilize prices and reduce the chances of large price swings. These market makers earn a profit from the difference between the buying price (the bid) and the selling price (the ask). This difference is known as the spread. Their role is crucial in maintaining efficient markets, allowing investors to trade easily without significant delays.