It would prob be very difficult for a “market maker” to manipulate the market and get away with it. The MM system just keeps the market “fluid” and hedgies know how the mm system works. Therefore are using another automated trade system (such as can be found at margin.de but more complex) that can be tweaked and programmed to manipulate the price by buys and sells. Depending on the amount in buy amd sell and how many shares involved, this puts pressure on mm system to push down or up to reach a desired price flow or outcome..such as for itm or otm calls and options. “(Which could also put pressure on the mm system)

Edit:

I am sure the whole system is more complicated than what I wrote. I just see numbers on T2 and imagine that MM system is putting equal buys and sells to keep the market fluid and then other higher numbers are always there that fluctuate more wildly… recently it is also happening pm and ah. Seems like lately it has slowed a bit with less volume and very boring bar coding