Their valuations differ by about 13%. That's close enough that I wouldn't call it "blown past".
Things change fast in this space. Anthropic had a big boost from having the premier coding model for a while, but GPT-5.5 has closed that gap at a time when a lot of Anthropic customers are looking for cheaper alternatives.
Anthropic is coming off of a recent change to their enterprise billing that substantially changed the pricing for many users. They were smart to do the fundraising before the effects of that change could fully propagate.
Things change fast in this space. Anthropic had a big boost from having the premier coding model for a while, but GPT-5.5 has closed that gap at a time when a lot of Anthropic customers are looking for cheaper alternatives.
Anthropic is coming off of a recent change to their enterprise billing that substantially changed the pricing for many users. They were smart to do the fundraising before the effects of that change could fully propagate.