A market maker is a broker-dealer who stands ready to buy or sell shares of the stocks in which it makes a market. When a transaction is proposed, the market maker will give a price at which it would be willing to effect that transaction.
The more market makers there are in a given stock, the more likely they are to bid against each other, and the price will more likely move to a true "market" price.
News 
Market Data 
Discover 
AI
