Bingo! Trading around the lowest offer or highest bid is one of the ways they "walk the market down". Oh ya, and it is a blatant violation of FINRA regulations. When you see that happen send a complaint to FINRA at:
You do not need to give you name if you don't want to. The more people who complain the more likely they will take some action. FINRA is much more likely to act than the SEC so it is worth your time (and it worked in the spring when they were doing the same thing).