Anthropic IPO: Polymarket Bets on an October Listing

Anthropic officially filed its confidential IPO application in the United States on June 1, 2026. Since then, betting has accelerated. As of August 17, Polymarket estimates the probability of a listing before October 31 at 69.5% and an arrival on the stock market before the end of the year at 87%. However, no official date has yet been communicated.

October Is Taking the Bets, Not the Calendar

After the $9.1 billion mega-deal signed with Riot, Anthropic is now preparing one of the most watched financial operations in the AI sector. The lab confirmed on June 1 that it had confidentially filed its IPO application in the United States.

The process is therefore well underway. But for now, Anthropic has announced neither listing date, price range, nor sought amount.

It is precisely this gap that Polymarket tries to fill. In the capture shared by CryptoPotato, the probabilities reached 2% before September 15, 10% before September 30, 70% before October 31, and 83% before December 31.

A consultation of the Polymarket public API, carried out on August 17 at 10:31 UTC, gave very similar figures: 1.65%, 10%, 69.5%, and 87%.

One detail is essential however. The contract is only validated if Anthropic shares are actually listed and open for trading before the scheduled date. The confidential filing alone is therefore not sufficient.

Betting is clearly focused on October. Between the September 30 deadline, estimated at 10%, and October 31 at 69.5%, the gap reaches 59.5 points. In other words, it is mainly the month of October that traders seem to target.

At the time of consultation, the market showed about $1.54 million in cumulative volume, $35,345 traded over 24 hours, and nearly $79,000 in liquidity. Interesting figures to measure contract activity, but which do not necessarily represent the opinion of major institutional investors.

Figures That Feed Expectations

The financial dossier explains why investors are already looking beyond the current year, without validating an IPO valuation. On May 28, Anthropic announced a $65 billion Series H fundraising, for a post-money valuation of $965 billion.

In the same statement, the company indicated that its annualized revenue had surpassed $47 billion at the beginning of May. Reuters reports on its side a 2028 revenue projection between $190 billion and $200 billion, attributed to two persons familiar with Anthropic’s finances. 

The division gives an order of magnitude of 4.0 to 4.3 times the current rate, but compares an annualized rate communicated by the company to a projection not published in an accessible S-1.

This extrapolation explains the valuation method observed by Reuters: bankers and investors use revenue multiples based on forecasts. The calculation remains demanding because Anthropic must finance processors, model training, inference, and recruiting before demonstrating that its margins will improve with scale.

Caution also applies to the market signal. A Stanford study on manipulation risk at Polymarket documented by Cointribune concerned Bitcoin contracts with very short maturity and does not prove manipulation of the Anthropic market. It does however remind that a contract price remains localized information, dependent on its liquidity and rules.

The Real Signal Will Come from the Prospectus

No verified source currently sets a firm public date, price range, or offer size. The Reuters dispatch published on June 1 specifies that Anthropic had not communicated the terms of the operation despite announcing the confidential filing.

This confidentiality gives the company the ability to prepare its operation while protecting its financial information from competitors and the public. It also leaves the door open to a delay if regulatory review, markets, or revenue projections no longer justify a listing in the fall.

The next test will therefore be documentary: a public prospectus, a price range, or a dated announcement from Anthropic will weigh more than a new Polymarket capture. Meanwhile, 69.5% only means that the “before October 31” contract was traded at that level at the observed time, not that the IPO is decided.

The market indeed places October at the center of the scenario, while Anthropic’s private figures feed the ambition of an extraordinary operation. The next steps will have to be read with the same caution as recent tensions at OpenAI: the public filing and financial terms will be the proof, while probabilities remain a sentiment indicator.