There was a time when I didn't understand this either. It's a critical calculation:
Company value = x Shares on issue = y Share price = x ÷ y
That's why the whole argument around not receiving the same % gains is inherently flawed. The company value will fluctuate at exactly the same % +/- based on how much capital the market is willing to invest / risk on any given day. The SP simply follows suit.
MC determines SP. Not the other way around. This is true 100% of the time, unless perhaps if you are day / swing trading.
Please take the time to understand this if you don't already. For the sake of all your investments.