Anthropic's revenue exploded in 2025. So did its losses.
Anthropic lost $42 billion in 2025, according to a draft IPO prospectus reviewed by Reuters. Revenue grew twelvefold over the same period, reaching nearly $4.6 billion. Reuters reporter Echo Wang, who reviewed the filing, found that almost a quarter of that revenue came from just two customers, neither of which was named. The prospectus itself has not been made public.
Those numbers put a real figure on what it costs to chase the AI race right now: Anthropic spent roughly nine dollars for every dollar of revenue it brought in during 2025. The customer concentration figure may matter more to IPO watchers than the growth rate does, since a business where a quarter of revenue rides on two accounts carries a risk that has nothing to do with how good the models are.
Every frontier AI lab is currently trading investor cash for growth at a similar clip. The real test comes only when investors start asking that ratio to move the other way.