Anthropic aims to match SpaceX's $75B IPO, which makes the float the number to watch

Anthropic intends to match or beat the size of SpaceX's initial public offering, according to a Bloomberg report citing anonymous sources and summarised by Fortune ^[1]. SpaceX raised $75 billion, or $86.2 billion once the over-allotment is counted ^[2], which means a company that has not yet named a price is briefing investors on a raise at the top of the record books ^[1][3].

The distinction that matters is between offering size and valuation, and Anthropic has so far signalled only the first. Fortune reports it is unclear what valuation the company is seeking, and that Bloomberg said CFO Krishna Rao skirted the question in recent briefings with investors ^[5]. The reference points are known. SpaceX carries a $1.77 trillion valuation ^[6], while Anthropic's last private mark was $965 billion, set in May ^[7]. Matching SpaceX on valuation would take roughly 1.8 times that mark, about $805 billion of additional value ^[10]. Matching it on raise size is a different exercise entirely: a $75 billion offering against a $965 billion valuation is a float of about 7.8 percent ^[11], and $86.2 billion is about 8.9 percent ^[12]. That is a large block of stock to place in one sitting, and it is the number to watch, because the float determines how much genuine price discovery happens rather than how big the headline is.

That price discovery is the consequence that reaches past Anthropic's own cap table. The $965 billion figure is currently the output of a negotiation among a small set of private investors ^[7]. A float converts it into a daily quote that every AI comparable, and every employee holding paper, gets marked against. Anthropic is expected to list in the coming months ^[8], while OpenAI is believed to be targeting a 2027 debut ^[9]. Whoever prices first sets the multiple the second one has to argue with.

Demand does not look like the binding constraint yet. Unitree, the Chinese robotics company, listed on Wednesday and its shares rose 460 percent on the first day of trading ^[13]. Fortune's assessment of the benchmark Anthropic is chasing is blunter than the pitch: there is nothing rational about SpaceX's valuation ^[14]. Supply of AI-linked paper is stacking up regardless. Broadcom is looking to raise $60 billion in debt for an AI chip financing deal ^[15], which alongside a $75 billion equity offering is $135 billion of AI-linked capital being called in a narrow window ^[16].

Three things to watch. Whether Rao eventually puts a valuation range in front of investors rather than a raise target, since a raise number without a denominator says nothing about dilution or price ^[5]. The percentage of the company actually offered, because 7.8 percent ^[11] behaves very differently in the aftermarket than a token slice. And the trade itself: if Anthropic prices at or above SpaceX's $75 billion ^[2] and then trades down, the $965 billion private mark ^[7] stops functioning as a floor for anyone raising off it.