CB- there have been several excellent posts concerning Market makers, their roles and affiliations, and yes it does seem as if they are left to police themselves and don't do a good job of it. Making decisions on stock investments would be much easier at the penny level if the MMs didn't have their own agenda and simply worked to try and stimulate trades. The unfortunate part is that everytime a stock sells, there is a buyer and a seller, allowing the MM to cloud the issue. The question of bid and ask prices is further complicated because often times both are controlled by a single MM
Perhaps one of the posters of those previous informative postings would chime in and save you some of the tedious work of scanning hundreds of posts....
glty
pete
Market Data 
Markets 
AI
