maybe the reason for the MM's cover...
the shake could be related to news coming down very soon... it has been known to happen... the MM's shake the stock hard and bring it down... sellers get out thinking it is going to drop hard, then it reverses and moves back up; causing some to chase it back.
MM's are allowed to inventory trading shares. Keep that in mind.
When the news breaks, sometimes big news, there is a run... that is where the MM's make their bonus money... on the gap.
so it is not hard to envision why some things happen in the market once you have tuned in to what the sides are doing and what happens after.
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