institutional Buyers and Sellers, wolves in sheep's clothing

Hello from Argentina,

It said that institutional BTC purchases don't affect BTC price on the open market, I would imagine that this can only be done to a certain extent, there must be a point when institutional buyer will not be able to keep purchasing BTC without spiking open market BTC price; when do you guys think this will be???

On the other hand, let's imagine institutions star selling off their BTC at once, will it plunge BTC open market prices?? No one talks about these two things, nor about the real possibility of total crypto market manipulation, since there is no law against cartelling on crypto world, can anyone care to comment on these two subjects?

Thanks