Shadow, I always heard that mm's have signals, I don't know how true that is. Anyway, here is what I heard on other boards:
100 sale- mm needs.
200 sale- mm needs shares bad- lots of orders can't be covered.
300 sale- mm is going to take price down to get shares.
400 sale- mm wants to trade sideways.
500 sale- mm wants gapping up or down depending which way the sale went(- +).
This is only rumor and is probably wrong, but this is something that is going around.
imo