But diversify into what?

If we assume this takes down the US economy and bonds, what then? International bonds/stocks? Won't those also be too entangled? Precious metals?

If there's a big AI bust, there will be no escaping it. Like 2008, the entire economy will slow down. This time it might even end in a war. A well diversified portfolio e.g. index funds will weather the storm and recover.

Build your emergency fund first if you don't have one. 6-12 months of salary in cash or CDs. Then dollar-cost average into well diversified equities. Don't watch them day-to-day. You're concerned about their value in 20-30 years, not tomorrow.

Nobody can tell you what to diversify into without information about what you are concentrated in.

Sure, spread investments across stocks and bonds and treasuries from different markets.

But you can also diversify more broadly beyond economic capital to cultural and social capital. Learn new skills and build networks of generalized reciprocity with others before you (or they) need help.

Those gold guys have been decrying the collapse the US economy for 25 years now, so you'll be in good company.