Invest in a standard index fund (like S&P500, etc)

Do nothing, as it was a hack, not a legitimate SEC ruling.

"How do I ensure I don't make any money from a flood of money pouring into an absolutely scarce digital asset"

I'm sure your performative nocoinering will feel really good in a year when you're wrong yet again.

Most 401ks let you choose the funds to invest in.

self direct?