If they are flipping and they can do it 3 or 4 times a day, day in & day out, that's one of the ways these MM's make money. They don't make a killing but they do chip away at making their money flipping back and forth and the fee's related to those trades is another revenue stream. So, it is what it is for now. Your right when you say big news does eventually hit the radar that they sure could get hurt but I doubt their hurt will be too much for they only invest 2500 to 5000 shares at a time, right?