The market says 39%. History points lower, and the difference comes down to timing.
Published August 25, 2026
Anthropic is more likely than the market implies to miss the October 1 deadline.
The market gives Anthropic roughly a 39% chance of completing the steps this contract requires before October 1, 2026. PastBehavior estimates 24%.
The gap is about timing, not about whether the IPO is real. Anthropic is clearly preparing to go public. Several steps still sit between where the company is today and what this particular contract asks for.
For this market to resolve YES, Anthropic needs to get much further than simply announcing an IPO. One of three things has to happen before October 1:
In practical terms, Anthropic needs to be near the finish line of its IPO by September 30.
Fact Anthropic has already announced an IPO once. On June 1, 2026 it confidentially filed a draft S-1 and published a notice saying so. That settled nothing, and the July and August versions of this market both resolved NO.
Large technology IPOs move through the same sequence almost every time. A confidential filing starts a private SEC review. The company then files its S-1 publicly, runs a roadshow, prices the offering, and trades the next morning.
The public filing is the step that carries the most information. Once it appears, the rest runs on a tight and fairly predictable clock.
| Company | Year | Public S-1 to pricing |
|---|---|---|
| Snowflake | 2020 | 22 days |
| SpaceX | 2026 | 22 days |
| Airbnb | 2020 | 23 days |
| Instacart | 2023 | 24 days |
| 2024 | 27 days | |
| Uber | 2019 | 28 days |
Slower cases exist. Rivian took 39 days. Circle took 64 after a volatility shock interrupted the window. In almost every slow case something identifiable went wrong or the company chose to wait.
The lesson is simple. Once a large technology company files its S-1 publicly, even the fastest deals have needed about three to four weeks to reach a price.
The clock becomes very tight if Anthropic does not file publicly by the end of August or very early September.
Reported The public filing on its own does not resolve this market. SpaceX filed publicly on May 20, 2026, naming Nasdaq and the symbol SPCX. The equivalent contract for June 1 was still trading a week later. SpaceX priced on June 11.
The evidence that Anthropic is moving toward an IPO is strong. That is not the question.
The question is whether the rest of the process happens fast enough to satisfy this contract before October 1. A company sitting on a fresh $65 billion also has no financing pressure forcing it onto any particular date.
The first PastBehavior analysis put the odds at 11%.
A second analysis was then run with the explicit job of attacking that answer. It found that the first forecast had underestimated how meaningful a late August public filing would be.
Companies do not publish an S-1 at a random moment. Bankers work backward from a target pricing date, since filing early hands competitors a full view of the financials for no benefit. A company that files at the end of August is usually already aiming at a near-term offering.
That correction moved the estimate to 24%, and 24% is the working PastBehavior forecast. Showing the revision matters more than defending the first answer.
Both numbers agree that Anthropic is close to a listing. They disagree about whether the closing stretch fits inside five weeks.
PastBehavior therefore sees the NO side as more attractive at the current market price.
The current PastBehavior signal is BID NO.
That rests on the historical pattern holding here. The estimate carries a working range of roughly 16% to 33%, so the disagreement with the market is real without being wide.
One thing matters far more than anything else.
Anthropic’s public S-1.
If it appears by the end of August or very early September, the probability should rise substantially. If nothing is on file by roughly September 8, the probability should fall sharply.
That makes this forecast testable in real time rather than only at resolution.
PastBehavior normally uses history to understand what companies are likely to do next. Those findings are hard to grade, because there is rarely a date on which anyone can check them.
Prediction markets supply the missing part. The prediction can be written down in advance, compared with the market, and checked against what actually happens.
Nothing here shows the method works yet. This is Prediction Market No. 002.
The forecast above is the permanent published record. This block tracks what the market has done since, using stored observations of the Kalshi contract. The PastBehavior estimate moves only at a dated update.
No post-publication market observation yet. Status: OPEN
No market observations stored yet for this contract.