If you have access to Level 2 quotes you can see the best bid and offers that they want to broadcast by each of the mms(only shows the best on their books, not the rest of their orders). You can not tell anything more than that. All retail customer orders must be shown as long as they are of the minimum volume standards for each exchange (mostly depends on the share price). An institutional or private client order or an order for the mm (and these are so much less than people think)can remain hidden.
There is no way to no for sure when a mm is finished with a large, say maybe a liquidation or dilution, order. Sometimes they lay back and let the market breath so they can smack it again, sometimes they are finished. As I said, its their world and we just try to get through it. Trade volume is always the answer to mm manipulations.
GLTY
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