Will Anthropic have the best AI model at the end of September 2026?
The move lacks solid trading support — treat the new probability with caution.
The pricing has weak support: healthy trading volume and market depth, a tight spread.
How credible was the move?
Three separate questions — a move can be genuine while the latest price is still settling. Methodology →
Move validity
Is the move backed by real trading and depth?
WeakThe pricing has weak support: healthy trading volume and market depth, a tight spread.
Consensus stability
Has the market settled at the new probability?
FormingMovement has slowed (9.5 points over six hours) but the market has not fully settled.
Contract clarity
Will the rules resolve without ambiguity?
HighThe resolution rules are relatively specific, with a named source and a defined deadline.
From the latest trade tape (most recent 200 prints) — a live activity sample, not a lifetime total.
What this market actually measures
This market will resolve according to the company which owns the model which has the highest arena rank based on the arena.ai Text Arena (Overall) when the table under the "Leaderboard" tab is checked on September 30, 2026, 12:00 PM ET. Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall-no-style-control with style control off (Adjustments: None…
This summary shows the opening of the venue's official rules. ProbCast has not yet generated an independent plain-English interpretation for this contract — review the full rules before relying on it.
View full official resolution rules
This market will resolve according to the company which owns the model which has the highest arena rank based on the arena.ai Text Arena (Overall) when the table under the "Leaderboard" tab is checked on September 30, 2026, 12:00 PM ET. Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market. Models will be ordered primarily by their leaderboard rank at the market’s check time. If two or more models are tied on rank, they will be ordered by their Arena score, including any underlying, unrounded, granular values reflected in the data below the leaderboard. If a tie still remains, alphabetical order of company names as listed in this market group will be used as a final tiebreaker (e.g., if the two models are tied by exact arena score, “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies first place under this ranking. The resolution source for this market is the arena.ai Text Arena (Overall). If this resolution source is unavailable at check time, this market will remain open until the leaderboard comes back online and will resolve based on the first check after it becomes available. If it becomes permanently unavailable, this market will resolve to "Other".
Resolution source:
Why the odds moved
The probability rose 9.5 percentage points over the last 24 hours (72.0% → 81.5%).
No verified catalyst has been linked to this move yet. ProbCast does not attribute moves to news without evidence connecting the timing of a specific report to the repricing.
What could move this market next?
- The market's deadline arrivesSeptember 30, 2026 at 11:59 PM ET
The contract must resolve based on what has happened by this date.
- Confirmation at the resolution source (arena.ai)
The rules name this source as the basis for settlement.
Derived from the contract's own mechanics as of Sep 3, 6:12 PM ET. ProbCast does not list scheduled meetings, announcements, or data releases it cannot verify.
Advanced analysis (experimental)
Research signals — these models are still accumulating the history needed for full validation, and they can disagree with the headline read. Model confidence: low · expected error ±27 pts.
What's happening
The price is actively repricing on real volume. The number is still moving — don't treat the latest print as settled consensus yet.