Difference is if corporations and funds can't hold bitcoin/crypto - you're back to $1/BTC. The whole value proposition of BTC hype bubble bursts if it's illegal in a major market like USA. Don't doubt some cyberpunk nuts will keep playing with it.
While BTC may burst, it wouldn't go to $1/BTC. it would go to a small percentage of what it is now, but still retain some value.
I haven't bought any Monero, but I saw this website the other day: https://localmonero.co/
If that's legitimate, it seems pretty easy.
I buy Monero by buying Litecoin at any exchange and then swap it for Monero using blocktrades.
Notably, Binance allows buying Monero directly.
Heck, even in American history we once tried to ban private ownership of gold bullion. The black market price of gold rose substantially.
That's a nonsense comparison. When governments impose capital controls it means their currency is already sinking and it's a last ditch attempt to prevent this inevitable scenario.
BTC valuation is entirely based on narratives about how it's going to replace standard currency in whatever story is popular, and from what I can see right now it's being pumped up by funds who can't find other good investments in this markets and are willing to play with crypto. If it's illegal for US funds/citizens to hold it/be involved with it - the selloff alone would kill the market instantaneously.
There's no reason to think that, say a Japanese pension fund, that's invested in Grayscale is going to say, "oh shoot, guess there's no possible way to allocate to this asset class now". They'll just reinvest that same allocation in a UK or Caymans domiciled fund.
If anything the 85% of crypto investors who aren't invested, will most likely hoard in anticipation of the policy being reversed. For better or worse the US government has extremely low credibility when it comes to long-term policy consistency. Almost any US policy can simply be waited out until Congress/White House flips parties.
Holdings would seem to be more reasonably assumed to be proportional to wealth [0], not GDP. The US has a significantly larger share of global wealth than it does of GDP.
[0] or maybe more-than-linearly related, since less-wealthy people will have more of their wealth in directly-used assets like tools, vehicles, and homes.
Bitcoin market swings on Elon Musks tweets, a full scale ban in the US would obliterate it.