401ks are run by investment banks and investment banks invest in OpenAI/Anthropic, but those aren't the same parts of the company in any meaningful way. The 401ks are in public companies or bonds.

Yeah, but those public companies are going to include the so called magnificent seven, so unless they're really really careful, there's still a ton of exposure in their 401k to AI if you think it's a bubble that's going to pop.