Anthropic has chosen Nasdaq for its October IPO, in the week OpenAI ruled one out

Anthropic has settled on Nasdaq for a listing it still hopes to complete in October, according to a person familiar with the plans who spoke to Business Insider.

The filing remains private, and the valuation is not fixed, though estimates circulating around the deal put it near $2trn.

For Nasdaq, the win completes a set. It took SpaceX earlier this year at a $1.75trn valuation, and with Anthropic it now holds both of the largest listings of a year that has otherwise been thin for technology flotations.

The New York Stock Exchange has historically collected the biggest debuts, which makes 2026 a marked break, and both venues are competing less for the fees than for the right to be seen as the natural home of every AI listing that follows.

In trading terms, Anthropic gains very little. No convincing evidence shows that companies perform better on one American exchange than the other, and the practical difference comes down to market-maker mechanics: the two run different processes for setting an opening price, and very large offerings can strain them.

Nasdaq’s systems failed on the first day of Facebook’s 2012 IPO, still the cautionary example whenever a listing of this size arrives.

Only Nasdaq-listed companies can enter the Nasdaq 100, which is the part that does matter. Index inclusion pulls passive money in behind a stock without anyone deciding to buy it.

Two days ago, Sam Altman told Fortune that OpenAI would not list in 2026, because “given everything happening with safety, right now would be an ill-advised moment to go public”.

Anthropic is proceeding towards a roadshow in the same month Altman is avoiding, and the two companies have reached opposite conclusions from an almost identical set of facts.

The safety warning that has dominated the past fortnight came from a former Anthropic researcher who resigned over safety, saying the labs are gambling with our lives, and whose post, according to Business Insider, put the risk of human extinction above 10 percent.

The company about to ask public markets for a valuation is the company the warning came from.

Anthropic filed confidentially at a $965bn valuation, appointed Morgan Stanley and Goldman Sachs to lead, arranged a $15bn credit facility alongside a timetable that lands days before the US midterms, and has been preparing to pitch investors a $30trn addressable market. A raise of $100bn would make it the largest flotation ever attempted.

Every valuation attached to it so far has come from people briefing reporters rather than from a prospectus.

That changes soon by rule: Anthropic must publish its financials at least 15 days before the roadshow opens. On an October timetable, the first numbers anyone can check are due within weeks.