rj2, the MM's who are actively buying and selling a stock are always going to have some interest in making a profit on the difference between bid/ask.
Its really not much different than what a bookie does, IMO.
The intensity of their interest, however, is going to wax and wane based on volume and price.
Some of the methods that they use to make their profits are probably hidden to most of us, by design.....perhaps like the methods that credit card companies use and try to hide from us.
The big players are not generally very anxious to reveal their methods.
IMO,that's probably just reality, not conspiracy-based thinking.
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