anyone can buy and sell in the middle if you use a full service broker. you can play in the spread all day long. some brokers wont allow you to di it with tripzero stocks but some will
doinit When I first started to trade stock My Nephew set down with me and explaine hor these little stocks works and since he had been trading for many years I lestened to him, He told me that the mm's have what he called their bucket , and he said they sold out of their bucket so was possible for them to sell thousands or maybe millions of shares without buying any. John
Market Data 
Markets 
AI
