Start offering a $99 course on how to profit from FB Libra. Doesn't matter if you don't know anything about it, because the people who buy shovels during a gold rush usually know even less.

Getting involved is risky - even if you are right (and I think you are), the price could still increase by a large amount for a long time before sense reasserts itself.

As Keynes apparently did not say: "The market can stay irrational a lot longer than you can stay solvent."

If you hit your trading / credit limits you could lose a lot of money despite being right in the long run.

And as Keynes definitely did say, "In the long run, we are all dead."

A rational person would observe that something with no intrinsic value could very well be overpriced far longer than you can afford to short.

Ironically it may be to buy something like bitcoin and sell when it goes up. Reasoning: a) there are obviously hype believers who will buy and push the price up when optimistic and b) they tend not to sell being believers whereas as a skeptic you can.

You can go on deribit.com or bitmex.com and buy put options or sell future contracts.

Scam others.