Benchmark Almanac

Prophet Arena

Claude Opus 5.5 86.2 leads since September 2026
Claude Opus 5.5 86.2 leads since September 2026
In use

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.

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.

Abstract of LLM-as-a-Prophet: Understanding Predictive Intelligence with Prophet Arena (arXiv:2510.17638, CC0)
25
Entries on its own leaderboard, 24 models we track
2
Launch posts list it, from 1 lab

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.

  1. 1 Claude Opus 5.5 86.2
  2. 2 GPT-6 Astra 86.2
  3. 3 Kimi K3.1 Pro 86.2
  4. 4 Gemini 4 Argon 86.0
  5. 5 Claude Fable 5.1 86.0
  6. 6 GPT-6.1 Sol 86.0
  7. 7 Gemini 3.8 Flash 86.0
  8. 8 Claude Haiku 5.5 85.9
  9. 9 Claude Sonnet 5.5 85.8
  10. 10 GLM-5.3 85.8
  11. 11 DeepSeek V4.1 Flash 85.7
  12. 12 GPT-6.1 Terra 85.7
  13. 13 GPT-6 Luna 85.6
  14. 14 Grok 4.6 85.6
  15. 15 Qwen 3.8 Max 85.6
  16. 16 Gemini 3.1 Pro 85.5
  17. 17 Mistral Large 4 85.4
  18. 18 Muse Wonder 85.3
  19. 19 Kimi K3 85.3
  20. 20 GLM-5.2 85.3
  21. 21 Claude Fable 5 84.9
  22. 22 GPT-5.6 Sol 84.8
  23. 23 DeepSeek V4 Pro 0813 84.5
  24. 24 Tencent Hy3 84.5
  25. 25 Foresight V3 84.3

Source: Official Prophet Arena leaderboard

#EntryScoreSettingDateSource
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 Gemini 4 Argon 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 Gemini 3.8 Flash 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 DeepSeek V4.1 Flash 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 Qwen 3.8 Max 85.6 OpenCode Harness Aug 2026 Official leaderboard
16 Gemini 3.1 Pro 85.5 OpenCode Harness Feb 2026 Official leaderboard
17 Mistral Large 4 85.4 OpenCode Harness Oct 2026 Official leaderboard
18 Muse Wonder 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 DeepSeek V4 Pro 0813 84.5 Fixed Context Aug 2026 Official leaderboard
24 Tencent Hy3 84.5 Fixed Context Jul 2026 Official leaderboard
25 Foresight V3 84.3 Fixed Context Official leaderboard
#ModelScoreSettingDateSource
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 Gemini 4 Argon 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 Gemini 3.8 Flash 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 DeepSeek V4.1 Flash 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 Qwen 3.8 Max 85.6 OpenCode Harness Aug 2026 Official leaderboard
16 Gemini 3.1 Pro 85.5 OpenCode Harness Feb 2026 Official leaderboard
17 Mistral Large 4 85.4 OpenCode Harness Oct 2026 Official leaderboard
18 Muse Wonder 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 DeepSeek V4 Pro 0813 84.5 Fixed Context Aug 2026 Official leaderboard
24 Tencent Hy3 84.5 Fixed Context Jul 2026 Official leaderboard
25 Inkling 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.

Google DeepMind Qwen xAI Z.ai Anthropic OpenAI
Own leaderboard 7 leaders

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.

On the benchmark’s own leaderboard Reported by the lab in its model card
0.00 20.0 40.0 60.0 80.0 100.0 2026 2027 0.00 20.0 40.0 60.0 80.0 100.0 2026 2027

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.

Thinking Machines
DateLaunch postScoreAs the post writes it
Jul 30, 2026 Inkling-Small Prophet Arena Brier Score (lower is better)
Jul 15, 2026 Inkling 0.162 Prophet Arena, Brier score 0.1617

More in Forecasting

All 13 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%