The Biden Administration and Congressional Dems are mulling a proposal to do the once unthinkable: tax gains from investments in securities (e.g. stocks) that haven't been cashed out yet. For example, if I purchased $50,000 in Bitcoin and then later the value my holdings has risen to $100,000, then that $50,000 "gain" would be liable to said tax even if, hypothetically, the value of said holdings were to crash the day after I paid taxes on it.
How do you think this would be implemented? Do you think it's a good idea in principle? In practice?