Scan: Will Anthropic have the best AI model on LiveBench (Coding) at the end of September 2026?

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: polymarket_direct resolution_source polymarket_related kalshi_related claude_news article_search wikipedia

Sub-questions (Fermi decomposition)

Which company's model currently holds the top Coding score on LiveBench.ai in the latest release, and by what margin over the second-place model?
Where do Anthropic's best models (e.g., Claude Opus/Sonnet latest versions) currently rank on the LiveBench Coding leaderboard, and how large is the gap to the leader?
Are there credible reports of major frontier model releases (OpenAI GPT-5.x, Google Gemini 3.x, xAI Grok 5, Anthropic Claude next-gen, DeepSeek, etc.) expected between now and September 30, 2026?
How frequently does the #1 spot in LiveBench Coding change hands, and how often has Anthropic held the top position historically?
When is the next LiveBench release/refresh expected, and could a new release before Sept 30 reshuffle the Coding rankings?
What do the sibling markets in this Polymarket group (OpenAI, Google, xAI, etc.) imply about the probability distribution, and do they sum to roughly 100%?

Planner reasoning

This market resolves on a specific leaderboard snapshot (LiveBench Coding column) on Sept 30, 2026, so the current state of that leaderboard and Anthropic's margin over competitors is the primary driver. Key uncertainties are which model currently leads, how close rivals (OpenAI, Google, xAI, DeepSeek, etc.) are, and whether any major model releases are expected before the check date. Polymarket's own price is the anchor, with related markets and news on upcoming model releases as secondary signals.

2. Research Parallel tool calls

tool	status	time	items	summary
polymarket_direct	OK	0.2s	1	## This Market's Polymarket Data Will Anthropic have the best AI model on LiveBench (Coding) at the end of September 2026? - Current price (probability): 75.60% - 7-day price change: -9.40% - 30-day price change: +12.10% - Total volume: $20,810 (USD notional) - Price range: 32.00% - 95.30% - Da
resolution_source	OK	3.2s	1	already_resolved=unclear; matches_criteria=True; last_updated=unknown. The fetched page only returned the site title 'LiveBench' with no visible leaderboard data, scores, or model rankings for the Coding category.
polymarket_related	OK	0.6s	19	Polymarket search over 3 keyword(s), kept 19 matches. keyword 'LiveBench': 8 markets \| keyword 'best AI model': 8 markets \| keyword 'coding model': 3 markets
kalshi_related	OK	41.0s	1	1 related markets / summaries. keyword 'LiveBench': no matches \| keyword 'best AI model': no matches \| keyword 'Anthropic': ok
claude_news	OK	27.7s	5	Based on available search results, here are key findings on the LiveBench Coding leaderboard and competitive landscape heading into late 2026: - Direct LiveBench.ai snapshot: The live leaderboard currently shows Claude 4.6 Opus Thinking High Effort at 74.5, followed by DeepSeek V4 Flash 0731 a
article_search	OK	46.8s	37	Fetched 37 unique articles across 5 queries (lookback=45d). 'LiveBench coding leaderboard top model': 10 articles \| 'Anthropic Claude new model release 2026': 10 articles \| 'OpenAI GPT new model coding benchmark 2026': 10 articles \| 'Google Gemini new model release coding benchmark': 10 articles \| '
wikipedia	OK	0.3s	3	Fetched 3 Wikipedia entries (0 missing pages).

3. Evidence Brief Sonnet 5 · 8199 chars

# Current state This is a snapshot-based resolution: the market resolves on whether Anthropic's best model tops the LiveBench Coding leaderboard specifically at the Sept 30, 2026 12:00 PM ET check. Per Claude-sourced live snapshot data, Claude (Opus 4.6 Thinking, High Effort) currently sits #1 at 74.5, with DeepSeek V4 Flash (74.2), GPT-5.2 Codex (74.0), and Gemini 3.6 Flash (73.6) clustered within ~1 point — an extremely thin, contestable lead rather than a locked-in outcome. # Timeline of key events - 2025 (late): Anthropic ships Sonnet 4.5, Haiku 4.5, Opus 4.5 in rapid succession — reported cadence of major releases roughly every few weeks (claude_news). - 2026-05: Anthropic valued at $965B in Series H round (Wikipedia) — confirms continued heavy investment/scale. - 2026-08-05: Meta launches "Muse Code" coding agent to compete with Anthropic/OpenAI (CNBC, confirmed). - 2026-08-10: Meta open-sources Muse Glimmer/Spark models (CNBC, confirmed) — competitive pressure from open-weight labs. - 2026-08-17: Alibaba releases Qwen3.8 models with strong coding claims (CNBC, confirmed). - 2026-09-03: OpenAI launches GPT-6 Astra; reported to already top LiveBench Reasoning category within days (felloai.com, reported — not independently verified). - 2026-09-06: CNBC reports "model fatigue" — Anthropic updates Fable/Mythos, Meta and Google ship enhancements, OpenAI ships GPT-6 Astra, all within one week (confirmed, general trend). - 2026-09-08: Cramer/CNBC coverage of GPT-6 Astra's market impact (confirmed as news event, not benchmark placement). - Current (as of research date, pre-Sept 30 2026 close): LiveBench Coding leaderboard reportedly shows Claude Opus 4.6 Thinking narrowly #1 at 74.5 vs DeepSeek V4 Flash 74.2 (claude_news synthesis, reported — not directly verified via resolution_source tool, which returned no extractable data). # Event Will Anthropic's top model hold the #1 Coding score on LiveBench.ai when checked Sept 30, 2026 12:00 PM ET? # Outcomes to forecast Yes (Anthropic #1) / No (any other company #1) # Kalshi market anchor No kalshi_direct data was returned for this ticker in the research (tool did not run or returned nothing). The only Kalshi-side data available is an unrelated sibling market (Anthropic IPO order, 91%) and a US-stakes market (19%) — neither informative for this question. **Treat Polymarket price (75.6% YES, per polymarket_direct) as the best available cross-platform proxy anchor**, with the caveat that it is not the actual Kalshi consensus. # Resolution source Fetched https://livebench.ai/#/?cats=Coding directly — page is JS-rendered and returned only the site title, no leaderboard data extractable. Cannot confirm current standings from primary source; must rely on secondary reporting (claude_news synthesis) which describes a live snapshot showing Claude Opus 4.6 Thinking at #1 (74.5) narrowly ahead of DeepSeek V4 Flash (74.2). Status not resolvable to certainty from tooling. # Sub-question answers 1. **Current #1 and margin** — Per claude_news synthesis of a livebench.ai snapshot: Claude 4.6 Opus Thinking (74.5) leads DeepSeek V4 Flash (74.2) by ~0.3 pts, with GPT-5.2 Codex (74.0) and Gemini 3.6 Flash (73.6) close behind — a razor-thin margin. 2. **Anthropic's rank** — Anthropic's Opus 4.6 is reportedly #1 itself (not trailing); this sub-question is effectively answered by #1 above. 3. **Upcoming frontier releases** — Confirmed: OpenAI shipped GPT-6 Astra (Sept 3, 2026), already topping LiveBench Reasoning per felloai (reported, unverified for Coding specifically). Meta, Google, Alibaba, DeepSeek all shipping frequent updates through Aug-Sept 2026. No Grok 5-specific data found in raw research. 4. **Historical #1 volatility** — No explicit historical churn-rate data provided by tools; qualitative evidence (claude_news, CNBC "model fatigue" article) indicates leaderboard reshuffles occur on roughly weekly-to-monthly cadence given release frequency across labs. 5. **Next LiveBench refresh timing** — Not directly answered by tools; LiveBench is described elsewhere as a continuously-updated benchmark, implying refreshes could occur multiple times before Sept 30 close, each capable of reshuffling rankings given sub-1-point gaps. 6. **Sibling market distribution** — Polymarket sibling markets: Anthropic 75.6%, OpenAI 3.8%, Google 0.05%, Meta 1%, Alibaba/Moonshot/Baidu/Z.ai ~0.05% each. Sum ≈ 80.5% (not 100%), leaving ~19.5% unaccounted — possibly reflecting "Other"/uncertainty or mispricing across a thin, low-volume market group. # Key facts (high-confidence, factual) 1. [polymarket_direct] Current Polymarket YES price: 75.6%, down 9.4% over 7 days, up 12.1% over 30 days; volume $20.8K; historical range 32%-95.3%. 2. [claude_news] Live snapshot shows Claude Opus 4.6 narrowly #1 in Coding (74.5) vs DeepSeek (74.2), OpenAI (74.0), Google (73.6) — gaps <1 point. 3. [CNBC, confirmed] OpenAI's GPT-6 Astra launched Sept 3, 2026, generating major market/competitive attention. 4. [CNBC, confirmed] "Model fatigue" — Anthropic, Meta, Google, OpenAI all released updates within the same week of early Sept 2026, indicating rapid, ongoing reshuffling potential. 5. [resolution_source] Direct livebench.ai fetch failed to return usable leaderboard data (JS-rendered); no independent confirmation of current standings possible via tooling. # Cross-market signals - Kalshi related: No direct/topical Kalshi market found; only tangential Anthropic IPO market (91% YES, uninformative). - Polymarket: Anthropic-best-model-on-LiveBench-Coding at 75.6%; broader "best AI model overall" Anthropic market much higher at 96.15% (higher volume, $737K) — suggesting stronger market confidence in Anthropic's overall dominance than in this specific narrow Coding-only metric. - Sportsbook implied: N/A. # Analyst opinions and speculation - claude_news synthesis frames outcome as "closely contested rather than a clear Anthropic lock" given sub-point margins and multiple labs' rapid iteration. - CNBC's "model fatigue" piece frames the competitive landscape as maximally volatile — near-weekly frontier releases from Anthropic, OpenAI, Google, Meta. - Caveat flagged by claude_news: several aggregator sites give conflicting model names/rankings, indicating benchmark data itself may be unstable/inconsistently reported. # Directional lean per outcome - **Yes (Anthropic)**: Supported by current (if accurate) narrow #1 position, high Polymarket price (75.6%), Anthropic's rapid release cadence (Fable, Mythos, Opus 4.6+), and much higher confidence in Anthropic's "best AI model overall" sibling market (96%). - **No**: Supported by extremely thin margins (<1 pt) versus DeepSeek/OpenAI/Google, active competitive releases (GPT-6 Astra, DeepSeek V4 Flash jump 65.5→74.2), high leaderboard volatility per "model fatigue" reporting, and inability to verify current standing directly from the resolution source. # Gaps / unknowns - No kalshi_direct price was retrieved for this exact ticker — true Kalshi consensus unknown; Polymarket used as substitute anchor. - Resolution source (livebench.ai) could not be verified directly; current standing relies solely on secondhand claude_news synthesis, itself sourced from unverified/inconsistent aggregators. - No confirmation whether GPT-6 Astra or DeepSeek V4 Flash have overtaken Claude specifically in the Coding category (only Reasoning category confirmed for Astra). - Historical churn frequency of LiveBench Coding #1 spot not quantified by any tool. - Sibling markets sum to ~80.5%, not 100%, indicating potential inefficiency/thin liquidity in this market group. # Calibration anchors - Polymarket YES price (proxy anchor): 75.6%, recent 7-day decline of -9.4pts suggests softening confidence. - Related sibling market ("best AI model overall - Anthropic"): 96.15%, indicating much stronger confidence in general dominance than this narrow, volatile Coding-specific metric. - Precedent: Benchmark leaderboards with sub-1-point margins historically flip within weeks given monthly-or-faster release cadences across at least 4 competing labs (Anthropic, OpenAI, DeepSeek, Google) — precedent argues for meaningful uncertainty despite current lead.

4. Forecasters 5 draws · Fable 5.1 + GPT-5.6 Sol

claude-fable-5-1

38% conf

Yes	68%
No	32%

No direct Kalshi price was available, so the Polymarket YES at 75.6% (down 9.4 pts over 7 days) serves as the anchor. The reported snapshot has Claude Opus 4.6 Thinking #1 at 74.5 but only 0.3 pts ahead of DeepSeek V4 Flash and within 1 pt of OpenAI and Google, and GPT-6 Astra (launched Sept 3, reportedly topping LiveBench Reasoning) does not yet appear in the coding snapshot, suggesting the data may be stale or that a reshuffle is pending. CNBC's 'model fatigue' reporting confirms near-weekly frontier releases across four-plus labs, so a sub-1-point lead is fragile over any remaining window. The resolution source could not be verified directly, and sibling markets summing to ~80% signal thin, possibly mispriced liquidity, so I shade modestly below the Polymarket anchor while keeping Anthropic the favorite given incumbency and its rapid release cadence.

claude-fable-5-1

38% conf

Yes	67%
No	33%

The only usable anchor is Polymarket at 75.6% YES (no Kalshi price retrieved), and it has softened 9.4 pts over the past week, coinciding with OpenAI's GPT-6 Astra launch (Sept 3), which reportedly already tops LiveBench Reasoning. The secondhand snapshot shows Claude Opus 4.6 Thinking at #1 in Coding by only ~0.3 pts over DeepSeek V4 Flash, with GPT-5.2 Codex and Gemini 3.6 Flash within 1 pt — and notably GPT-6 Astra does not appear in that snapshot, suggesting it is either stale or Astra's Coding score is pending, a real downside risk. The resolution source could not be verified directly and aggregators report inconsistent rankings. Weighing the incumbent lead and Anthropic's fast release cadence against razor-thin margins, weekly frontier releases across four labs, and the unpriced GPT-6 Coding risk, I shade modestly below the Polymarket proxy to ~0.67 YES.

claude-fable-5-1

36% conf

Yes	70%
No	30%

The best available anchor is Polymarket at 75.6% YES (no Kalshi-direct price retrieved), with a secondhand snapshot showing Claude Opus 4.6 Thinking narrowly #1 in LiveBench Coding (74.5 vs DeepSeek V4 Flash 74.2, GPT-5.2 Codex 74.0). The incumbency and Anthropic's rapid release cadence support Yes, but the sub-1-point margin, GPT-6 Astra's Sept 3 launch (already reportedly topping Reasoning), the 'model fatigue' wave of competitor releases, and the -9.4pt 7-day price decline argue for shading slightly below the anchor. The resolution source could not be verified directly, and aggregator rankings are described as inconsistent, adding tail risk in both directions. I land at 0.70 Yes, modestly below the Polymarket proxy.

gpt-5.6-sol

58% conf

Yes	71%
No	29%

The best available anchor is Polymarket at 75.6% YES because no direct Kalshi price was retrieved. Anthropic is reportedly already #1, which favors Yes, but its 0.3-point lead over DeepSeek and similarly small gaps over OpenAI and Google leave it vulnerable to ordinary leaderboard movement. Rapid September releases and continuously updated scoring create meaningful reshuffling risk before the snapshot, while the inability to verify the standings directly on LiveBench adds source uncertainty. I therefore shade below the proxy-market consensus to 71% YES.

gpt-5.6-sol

58% conf

Yes	70%
No	30%

The reported current ranking points toward Yes because Anthropic leads, but its 74.5 score is only 0.3 points above DeepSeek and 0.5 above OpenAI. Rapid releases from several labs and continuously updated rankings create a meaningful chance of a change before the September 30 snapshot. I anchor on Polymarket's 75.6% YES proxy, then move modestly downward because the standings could not be verified from LiveBench directly and the proxy market is relatively thin. Anthropic remains favored because it already holds the reported lead and no rival is confirmed to have surpassed it in Coding.

6. Final plain mean of 5 draws

69% (46% confidence)

Yes: 69% No: 31%

Mean of 5 draws (0.68, 0.67, 0.70, 0.71, 0.70). No direct Kalshi price was available, so the Polymarket YES at 75.6% (down 9.4 pts over 7 days) serves as the anchor. The reported snapshot has Claude Opus 4.6 Thinking #1 at 74.5 but only 0.3 pts ahead of DeepSeek V4 Flash and within 1 pt of OpenAI and Google, and GPT-6 Astra (launched Sept 3, reportedly topping LiveBench Reasoning) does not yet appear in the coding snapshot, suggesting the data may be stale or that a reshuffle is pending. CNBC's 'model fatigue' reporting confirms near-weekly frontier releases across four-plus labs, so a sub-1-point lead is fragile over any remaining window. The resolution source could not be verified directly, and sibling markets summing to ~80% signal thin, possibly mispriced liquidity, so I shade modestly below the Polymarket anchor while keeping Anthropic the favorite given incumbency and its rapid release cadence.

Pipeline Timing

Total pipeline time: 115.3s

Per-tool research timings shown in the Research section above.