The point of prices is to find the value of things, so resources can be better allocated. It is not about fairness.
By the way, share value is only a guess about future production in the next 10 to 20 years. It is not wealth that exists today, and it cannot be consumed.
So you cannot take that wealth from the rich and "distribute" it. What you are really doing is taxing the poorest people.
If Microsoft is guessed to make more profits in 5 years, its share value grows, but no physical wealth has been created today. So if you take that "wealth" and use it to buy cars, you are taking those cars from the poorest person who would have bought them otherwise, because resources are scarce.
Those extra cars you are trying to get do not exist just because Microsoft's share valuation grew overnight.