Prophet Arena
Models and agents forecast open Kalshi prediction-market events and are scored once the events resolve. The live board ranks a difficulty-adjusted Arena score and also reports calibration error and market return.
ICLR 2026. Models appear once they reach 50 resolved events, in fixed-context and agentic harness tracks.
- Made by
- UChicago SIGMA Lab with Kalshi
- Released
- October 2025
- Kind
- Real-world events
- Level
- Expert
- Scored
- Settled by events
- Answers
- Prediction
- Tasks
- All public
- Strongest model tested
- GPT-6 Astra #3 on the capability index
- Last in a launch post
- July 2026
- Last model added
- October 2026
- Scores refreshed
- November 12th, 2026
In the authors’ words
Forecasting is not only a fundamental intellectual pursuit but also is of significant importance to societal systems such as finance and economics. With the rapid advances of large language models (LLMs) trained on Internet-scale data, it raises the promise of employing LLMs to forecast real-world future events, an emerging paradigm we call "LLM-as-a-Prophet". This paper systematically investigates such predictive intelligence of LLMs. To this end, we build Prophet Arena, a general evaluation benchmark that continuously collects live forecasting tasks and decomposes each task into distinct pipeline stages, in order to support our controlled and large-scale experimentation. Our comprehensive evaluation reveals that many LLMs already exhibit impressive forecasting capabilities, reflected in, e.g., their small calibration errors, consistent prediction confidence and promising market returns. However, we also uncover key bottlenecks towards achieving superior predictive intelligence via LLM-as-a-Prophet, such as LLMs' inaccurate event recalls, misunderstanding of data sources and slower information aggregation compared to markets when resolution nears.
Claude Opus 5.5 leads with 86.2
Best score per entry from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best. Names in gray aren't in our model list: fine-tunes, agent systems, products and older models. They don't count toward leaders.
Claude Opus 5.5 leads with 86.2, claims included
Best score per model from every source, including labs’ own numbers and claims Epoch AI collected from reports and papers. Labs pick their own settings, so a claim can beat an independent run of the same model.
- 86.2 Claude Opus 5.5
- 86.2 GPT-6 Astra
- 86.2 Kimi K3.1 Pro
- 86.0
Gemini 4 Argon
- 86.0 Claude Fable 5.1
- 86.0 GPT-6.1 Sol
- 86.0
Gemini 3.8 Flash
- 85.9 Claude Haiku 5.5
- 85.8 Claude Sonnet 5.5
- 85.8 GLM-5.3
- 85.7
DeepSeek V4.1 Flash
- 85.7 GPT-6.1 Terra
- 85.6 GPT-6 Luna
- 85.6 Grok 4.6
- 85.6
Qwen 3.8 Max
- 85.5
Gemini 3.1 Pro
- 85.4
Mistral Large 4
- 85.3
Muse Wonder
- 85.3 Kimi K3
- 85.3 GLM-5.2
- 84.9 Claude Fable 5
- 84.8 GPT-5.6 Sol
- 84.5
DeepSeek V4 Pro 0813
- 84.5
Tencent Hy3
- 84.3 Foresight V3
- 1 Claude Opus 5.5 86.2
- 2 GPT-6 Astra 86.2
- 3 Kimi K3.1 Pro 86.2
- 4
Gemini 4 Argon 86.0
- 5 Claude Fable 5.1 86.0
- 6 GPT-6.1 Sol 86.0
- 7
Gemini 3.8 Flash 86.0
- 8 Claude Haiku 5.5 85.9
- 9 Claude Sonnet 5.5 85.8
- 10 GLM-5.3 85.8
- 11
DeepSeek V4.1 Flash 85.7
- 12 GPT-6.1 Terra 85.7
- 13 GPT-6 Luna 85.6
- 14 Grok 4.6 85.6
- 15
Qwen 3.8 Max 85.6
- 16
Gemini 3.1 Pro 85.5
- 17
Mistral Large 4 85.4
- 18
Muse Wonder 85.3
- 19 Kimi K3 85.3
- 20 GLM-5.2 85.3
- 21 Claude Fable 5 84.9
- 22 GPT-5.6 Sol 84.8
- 23
DeepSeek V4 Pro 0813 84.5
- 24
Tencent Hy3 84.5
- 25 Foresight V3 84.3
Source: Official Prophet Arena leaderboard
- 86.2 Claude Opus 5.5
- 86.2 GPT-6 Astra
- 86.2 Kimi K3.1 Pro
- 86.0
Gemini 4 Argon
- 86.0 Claude Fable 5.1
- 86.0 GPT-6.1 Sol
- 86.0
Gemini 3.8 Flash
- 85.9 Claude Haiku 5.5
- 85.8 Claude Sonnet 5.5
- 85.8 GLM-5.3
- 85.7
DeepSeek V4.1 Flash
- 85.7 GPT-6.1 Terra
- 85.6 GPT-6 Luna
- 85.6 Grok 4.6
- 85.6
Qwen 3.8 Max
- 85.5
Gemini 3.1 Pro
- 85.4
Mistral Large 4
- 85.3
Muse Wonder
- 85.3 Kimi K3
- 85.3 GLM-5.2
- 84.9 Claude Fable 5
- 84.8 GPT-5.6 Sol
- 84.5
DeepSeek V4 Pro 0813
- 84.5
Tencent Hy3
- 0.16
Inkling
- 1 Claude Opus 5.5 86.2
- 2 GPT-6 Astra 86.2
- 3 Kimi K3.1 Pro 86.2
- 4
Gemini 4 Argon 86.0
- 5 Claude Fable 5.1 86.0
- 6 GPT-6.1 Sol 86.0
- 7
Gemini 3.8 Flash 86.0
- 8 Claude Haiku 5.5 85.9
- 9 Claude Sonnet 5.5 85.8
- 10 GLM-5.3 85.8
- 11
DeepSeek V4.1 Flash 85.7
- 12 GPT-6.1 Terra 85.7
- 13 GPT-6 Luna 85.6
- 14 Grok 4.6 85.6
- 15
Qwen 3.8 Max 85.6
- 16
Gemini 3.1 Pro 85.5
- 17
Mistral Large 4 85.4
- 18
Muse Wonder 85.3
- 19 Kimi K3 85.3
- 20 GLM-5.2 85.3
- 21 Claude Fable 5 84.9
- 22 GPT-5.6 Sol 84.8
- 23
DeepSeek V4 Pro 0813 84.5
- 24
Tencent Hy3 84.5
- 25
Inkling 0.16
Sources: Official Prophet Arena leaderboard and labs’ model cards
| # | Entry | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Opus 5.5 | 86.2 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 2 | GPT-6 Astra | 86.2 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 3 | Kimi K3.1 Pro | 86.2 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 4 | | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 5 | Claude Fable 5.1 | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 6 | GPT-6.1 Sol | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 7 | | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 8 | Claude Haiku 5.5 | 85.9 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 9 | Claude Sonnet 5.5 | 85.8 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 10 | GLM-5.3 | 85.8 | OpenCode Harness | Aug 2026 | Official leaderboard |
| 11 | | 85.7 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 12 | GPT-6.1 Terra | 85.7 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 13 | GPT-6 Luna | 85.6 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 14 | Grok 4.6 | 85.6 | OpenCode Harness | Aug 2026 | Official leaderboard |
| 15 | | 85.6 | OpenCode Harness | Aug 2026 | Official leaderboard |
| 16 | | 85.5 | OpenCode Harness | Feb 2026 | Official leaderboard |
| 17 | | 85.4 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 18 | | 85.3 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 19 | Kimi K3 | 85.3 | OpenCode Harness | Jul 2026 | Official leaderboard |
| 20 | GLM-5.2 | 85.3 | OpenCode Harness | Jun 2026 | Official leaderboard |
| 21 | Claude Fable 5 | 84.9 | Fixed Context | Jun 2026 | Official leaderboard |
| 22 | GPT-5.6 Sol | 84.8 | Fixed Context | Jul 2026 | Official leaderboard |
| 23 | | 84.5 | Fixed Context | Aug 2026 | Official leaderboard |
| 24 | | 84.5 | Fixed Context | Jul 2026 | Official leaderboard |
| 25 | Foresight V3 | 84.3 | Fixed Context | Official leaderboard |
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Opus 5.5 | 86.2 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 2 | GPT-6 Astra | 86.2 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 3 | Kimi K3.1 Pro | 86.2 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 4 | | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 5 | Claude Fable 5.1 | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 6 | GPT-6.1 Sol | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 7 | | 86.0 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 8 | Claude Haiku 5.5 | 85.9 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 9 | Claude Sonnet 5.5 | 85.8 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 10 | GLM-5.3 | 85.8 | OpenCode Harness | Aug 2026 | Official leaderboard |
| 11 | | 85.7 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 12 | GPT-6.1 Terra | 85.7 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 13 | GPT-6 Luna | 85.6 | OpenCode Harness | Sep 2026 | Official leaderboard |
| 14 | Grok 4.6 | 85.6 | OpenCode Harness | Aug 2026 | Official leaderboard |
| 15 | | 85.6 | OpenCode Harness | Aug 2026 | Official leaderboard |
| 16 | | 85.5 | OpenCode Harness | Feb 2026 | Official leaderboard |
| 17 | | 85.4 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 18 | | 85.3 | OpenCode Harness | Oct 2026 | Official leaderboard |
| 19 | Kimi K3 | 85.3 | OpenCode Harness | Jul 2026 | Official leaderboard |
| 20 | GLM-5.2 | 85.3 | OpenCode Harness | Jun 2026 | Official leaderboard |
| 21 | Claude Fable 5 | 84.9 | Fixed Context | Jun 2026 | Official leaderboard |
| 22 | GPT-5.6 Sol | 84.8 | Fixed Context | Jul 2026 | Official leaderboard |
| 23 | | 84.5 | Fixed Context | Aug 2026 | Official leaderboard |
| 24 | | 84.5 | Fixed Context | Jul 2026 | Official leaderboard |
| 25 | | 0.16 | Jul 2026 | Lab model card |
Labs report scores for 1 model in their cards. Switch the scores above to rank them together.
7 models have held number one on the official leaderboard since its release in October 2025 7 models have held number one with claims included since its release in October 2025
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Official Prophet Arena leaderboard
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Sources: Official Prophet Arena leaderboard and labs’ model cards
One lab put it in a launch post in the last six months
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| Jul 30, 2026 | Prophet Arena Brier Score (lower is better) | ||
| Jul 15, 2026 | 0.162 | Prophet Arena, Brier score 0.1617 |
More in Forecasting
- ForecastBench In use Models give probabilities for 500 auto-generated questions per round about future events, drawn from prediction markets and time-series datasets. Forecasts are scored with difficulty-adjusted Brier scores once the questions resolve. GPT-5.5 0.11
- Echo General AI Prediction Leaderboard Not in model cards Models forecast unresolved events drawn from prediction markets, synthesized news questions and expert-written questions. Forecasts made at aligned times are compared in pairwise battles, and an Elo fit ranks the models.
DeepSeek-V4-Pro 1,017
- Human Behavior Bench Not in model cards Models predict how specified groups of U.S. adults answer closed survey questions, as a distribution over options. Scored as 1 minus total variation distance.
Gemini 4 Argon 80.6
- BTF-3 Not in model cards Agents forecast already-resolved binary and numeric questions while researching a frozen snapshot of the web. Scoring pools Brier and ranked probability scores. Claude Opus 5 0.12
- FutureX Not in model cards Agents predict upcoming events collected daily from 195 websites in 11 domains, within a one-week window. Answers are scored once real results are crawled, with harder tiers weighted more. Grok 4 27.9
- KellyBench Not in model cards Agents bet through a simulated 2023 to 24 English Premier League season with historical data. The score is long-term bankroll growth. GPT-5.4 -7.90%