Well the idea that the price of a stock represents the actual value of the company can be complicated but the realization that it's super hard to figure out what the actual value of a company really is, because figuring that out really requires a crystal ball, because you need to know exactly how much money the company will earn in the future, among other things.

None of us have that crystal ball, so market participants try to guess at the future. It's not difficult to believe that those guesses can swing a lot in a single day. Just trying to figure out whether or the Hormuz will be open next week can give you whiplash.