1) I don't buy the arguments that BTC will fix societal problems, or that it will be a reserve currency. Despite that, I don't see why one can't profit from it. Sure, you can complain that it’s a bubble, but why does this bubble keep popping and resurrecting? As Colm O'Shea said

2) (paraphrased), just because something is a bubble, doesn't mean you shouldn't participate; the trick is to do it in a risk-controlled way.
Isolating the major risks to BTC, I can think of 1) Exchanges are banned 2) People are offered alternative investment vehicles with low

3) risk and high yield (Eg, US10Ys at 15%).
The easiest way I can think of to catch some upside of BTC/cryptos is to invest in the banks (I can think of one in particular) that provide financial services to crypto exchanges.
Increased crypto prices spurs activity on exchanges and

4) thus increases revenue to exchange-catering banks.
This hedges both risks: If all exchanges suddenly disappear, well the banks still have other forms of revenue to fall back on; sure it won't help them if crypto exchanges get banned, but its unlikely the stock goes to zero.

5) If US10Ys suddenly spike to 15%, there's probably a good chance that banks in general profit from it anyway, but I think we can all agree, US10ys aren’t going 2-digits anytime soon.

6) A trade like this can be hedged against bank-specific risks, like shorting XLF or putting on curve flattening trades to isolate the crypto-profit related component.

Just a thought.