I'm not sure about the rules because I don't follow them that closely, and without access to Level III it's impossible to tell who is doing all the accumulating. This is where the MM's can get up to all kinds of tricks and we will never know about it. It is also not uncommon for the MM's to share between themselves, one can be fronting the market and can then pass the shares between them.
It's a rigged game from the beginning as far as retail traders goes, lol