Only in the same sense that Lehman collapsing caused the 2008 crash. Nothing is monocausal, and crashes rarely happen all at once, but I expect it to be a big “uh oh” moment for investors.
Lehman’s market cap was an order of magnitude smaller than the current OpenAI valuation, I think even in inflation-adjusted terms. The intuition that a private company is small and can’t pose systemic risks just isn’t true anymore.