Answer: If by stocks you mean real assets of real companies of real productive capabilities then anyone who is also interested in tying their future to the only two things--according to Objectivism--that you can really count on: life and production.
But if by stocks you mean worthless pieces of paper then either: a) no one or b) fools yet unborn.
My advice: make sure your stocks are of the first kind.
P.S.
TBC
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