First off, you do not understand that Bitcoin has it's own decentralized exchange called mining.  Mining is demand.  There is no "may" about it.  Demand in comparison to supply hugely increases on the demand side and the centralized exchanges are forced to follow

Secondly, most Bitcoins are horded like the movie Leprechaun.  The entire supply of Bitcoin isn't just sitting on the exchange sell side wall.  The float is highly affected by daily mined supply, it's not a small factor.  In the following picture, there's only 16,000 coins until the price is $800 on Finex.  If you just started randomly buying off that wall with the goal of reaching $800, most of them would probably get pulled on the way and you'd only need to buy something like 1/4th of them (at least post halving).  Then all secondary, non-leading exchanges just pull their walls and price goes up without a fight even occurring.

You'll also have people who are just completely stupid and try to short at $450 pumping it to the moon through margin calls.