Assume that Anthropic, OpenAI and SpaceX all IPO and get included in SPY with the new fast listing rules. They are likely to be worth $3-4T combined, which means 'retail' investors are going to have perhaps 5% of their portfolio in it.
_Arugably_ that's a pretty fair allocation for retail investors to have to these "moonshot" style companies.
Also - if any one of these IPOs don't go well; I suspect the other(s) will have to postpone, further reducing exposure.