Buy a few... due you mean MM, or private individuals, like the bashers on LieHub?  I could subscribe to the theory that several MM colluded to manipulate... but then I think WHY?   One would jump first to money of course, but would the reward be worth the risk?  Even if ALL the volume today was manipulation (which we all know is unlikely) how much could they gain vs what they could risk losing if caught?  Catching them is a big if I know, but it is a possibility that would need to be taken into account.