1) The market value of a company is true, aka the owners of this company must be taxed for the real value growth in their portfolio (since it constitutes income), even if they do not sell
2) It’s a casino, a share is just a ticket that may worth nothing or a billion. In that case we don’t need tax protections. The owners of the tickets must be taxed only when they cash out. The governments should actively disincentivize gambling into this and ensure the pensions of its citizens by funding public projects and enabling future growth.
You cannot have it both ways.