If the casino is bubbling, the bubble component and the realistic value component become impossible to distinguish.

You could eliminate the bubble component by eliminating speculation and making it impossible to sell shares within - say - a year of purchase. That would turn casino transactions into more thoughtful and measured investment transactions.

Of course that's not going to happen, because no one in the casino wants to have their toys taken away. And also because a lot of 'growth' is generated by imaginary casino value artificially inflating expectations.