Market Maker Spread

This is the difference between the price at which a Market Maker is prepared to buy a security and the price at which they are willing to sell it. This is the difference between a Market Maker's bid and ask for a given security.

Since each Market Maker positions itself to either buy or sell inventory at any given time, each individual Market Maker spread is not indicative of the market as a whole. The spread for the market would be represented by the Inside Market.