Traders on prediction market Kalshi have sharply cooled on the prospect of Anthropic announcing an initial public offering before December, after pricing the event near 90% only a week earlier.

Odds on the contract fell to 57%, down from close to 90% just seven days ago. A drop of more than 30 points in a week amounts to a genuine repricing, not a rounding error. A crowd that recently treated a near-term announcement as close to a sure thing now sees it as only slightly better than a coin flip.

Kalshi contracts resolve based on whether a defined event occurs, meaning their traded prices function as a running gauge of the crowd's implied probability. That makes the speed of this decline particularly notable.

What the Market Is Pricing

Research compiled on the contract puts current Kalshi pricing in a 57-61% range for Anthropic officially announcing an initial public offering by December 1, 2026. That is a steep fall from late October, when estimates reached as high as 90%.

The longer-dated contract tells a somewhat calmer story. As of early November, the market was pricing a 69-70% probability of an announcement before January 1, 2027.

In other words, traders have not abandoned the idea of an Anthropic listing. They have largely pushed their expected timeline back and lowered their conviction along the way.

Money is following the debate. Trading volume on the relevant Kalshi contracts has exceeded $4.9 million, which is meaningful liquidity for a single corporate-event question.

One detail matters a great deal here: how Kalshi decides what counts. The platform defines an "official announcement" based on confirmations from major news outlets.

How the Odds Got So High

The spike toward 90% had a clear catalyst. According to the research, Anthropic publicly filed its Form S-1 with the US Securities and Exchange Commission (SEC) on October 26, 2026.

The S-1 is the registration statement US companies file with the SEC before shares can be offered to the public — a step that signals intent to list but does not, by itself, fix a listing date.

The filing reportedly lays out plans to list on Nasdaq under the ticker "ANT," with Goldman Sachs and Morgan Stanley serving as lead underwriters. Unsurprisingly, the S-1 initially gave traders a jolt of optimism about a near-term listing.

Many had anticipated a mid-November listing. As that window approached without the kind of confirmation the contract requires, expectations cooled.

The Numbers Behind the Hype

Anthropic was founded in 2021 by former OpenAI researchers and is best known for its Claude family of language models. Its financials, as described in the research, go a long way toward explaining why investors are paying close attention.

The company reported $16.3 billion in revenue for the first half of 2026, representing growth of more than 1,300% year-over-year. Anthropic also posted its first operating profit in the second quarter.

The bottom line looks very different, however. Anthropic's half-year net loss came to $80.7 billion, driven largely by significant non-cash fair-value adjustments — items that weigh on reported results without cash actually leaving the company, which is why the same period can hold both an operating profit and an enormous net loss.

The valuation figures are enormous in their own right. Anthropic raised a $65 billion Series H round in May 2026, which left its last private valuation at $965 billion. Rumored IPO targets reportedly range between $1.5 trillion and $2 trillion.

What This Means

The gap between the December and January contracts is the most useful signal here. A roughly 12-point spread suggests traders see a delay as more likely than a cancellation, a considerably less dramatic read than the headline drop implies.

The valuation leap is another pressure point. Moving from a $965 billion private mark to a rumored $1.5 trillion to $2 trillion public target would require public market investors to buy into an even bigger story than private backers already have. The two figures are also set differently: a private valuation is negotiated with a limited pool of investors in a single funding round, while a public listing has to be priced by a far broader market.

From here, the reference points are fixed rather than speculative: a December 1, 2026 deadline for the near-dated contract, a January 1, 2027 deadline for the longer-dated one, and Kalshi's rule that an official announcement counts only when confirmed by major news outlets.

Until then, the market is sitting at 57% — optimism with an asterisk, and the asterisk got a lot bigger this week.

Disclosure: The original report was edited by Estefano Gomez.