What you have written is correct... but you must remember they can sell first then buy later... so yesterday the bid was pulled up to .148 (the ask was .1485 which does not matter)..... now today the ask is @ .14... a trade 0f 15,000X.008 shares is 120 dollars profit... remeber the FD is not accounted for for three business days.... so this short postion that would not get noticed... an MM by moving the spread and controling the price they can & do make money (this is my assertion).... of course this can not happen on all stocks... low volume BB stocks that trade overseas are the prime candidates for stock tampering..... This is just observations over the years... the fact to remember MM's do hold shares they do make the market....