I have to pay taxes on my house based on unrealized gains, and to unlock those gains I would have to become homeless (which sucks worse than becoming stockless). If I don't pay the tax on that 'unrealized value' I lose the actual asset. But please tell me how unreasonable taxing unrealized stock gains would be, and how doing taxing unrealized gains is unheard of, irrational, and would destroy the market that created those gains (I guess like how property taxes have decimated housing prices?).