> the numbers we're discussing here are the amount they'll raise from the IPO

No, the "valuation" numbers are the market cap at the moment of IPO. The amount raised is that multiplied by the amount of shares issued by Anthropic (as opposed to by existing shareholders like investors and employees -- that combined number is the float) at the IPO.

Sorry, yes, that. The bigger point still stands, though — given a fixed fraction of shares they're offering, the valuation gives you the amount raised, and that makes the number interesting.