Particular market maker facilitating the order for the trader or investor. However, under different circumstances market makers fill orders for themselves, when they get filled it's never good. For example, market makers are in it to make a few bucks here and there, so if a retail investors sells on the small blocks it adds to the market maker pile, thus they turn around and sell it for only a couple of ticks up, thus, that's why it makes it harder for to this to run because bid whackers sell in to the bid. In some instances, where there is the same market maker is on both ask and bids and when someone bid whacks, that same market maker will add to his pile on the ask. When someone sells into the bid to the market maker with large or small blocks, it only makes it harder to go up because the psychology of OTC is if there is large block on the ask after market maker got his order fills on the bid is that is a big block to slap thus hinders the move to the upside and incites more sellers into the bid.