Companies going public like to put a number on the market they could win. It is called the total addressable market. Anthropic doesn’t use the term, but it gives a number that does the same job. It says the work done by the world’s knowledge workers, people paid to think, write, analyse and decide, was worth more than US$40 trillion in 2025. Its near-term opportunity, it says, is to make that work more productive.

That tops SpaceX, which listed earlier this year. Its prospectus claimed “the largest actionable total addressable market in human history”, at US$28.5 trillion. US$26.5 trillion of that was AI.

Where does US$40 trillion come from? Anthropic took what American knowledge workers earn, using US government wage data, and scaled it up to the whole world. So it is, roughly, the world’s salary bill for knowledge workers. That is about a third of the world’s entire economy, which the filing puts at more than US$118 trillion in 2025.

We’d treat it as a ceiling, not a forecast. Anthropic’s revenue at April to June’s pace is about US$46 billion a year, roughly 0.1% of US$40 trillion. Even 1% would be US$400 billion a year.And the two big numbers overlap. SpaceX’s AI market and Anthropic’s knowledge-work market are largely the same money. SpaceX, which owns xAI, is chasing it too, while also renting Anthropic a big share of its computing.