Will Anthropic have the best AI model at the end of November 2026?

- [2026-10-15] The resolution page, rendered live, shows the Text Arena Overall board (style control off, 416 models, 8.83M votes). At #1 is gemini-4-argon-high (Google), 1532 ±9, marked Preliminary, 4,904 votes. #2 is claude-opus-5.5-high (Anthropic), 1516 ±7, 8,300 votes. #3 is claude-fable-5.1-max, 1512. #4 is claude-opus-5-max, 1508. #5 is claude-opus-5-high, 1503. #6 is claude-opus-4-6-high, 1502. Meta's muse-wonder-max is #7 at 1501. The best OpenAI model on the page is gpt-5.5-high at #28 (1471); I saw no other OpenAI entry above it except gpt-5.6-sol-xhigh at #43 (1457). I saw no GPT-6 Astra on the board. The best SpaceXAI entry is grok-4.20 at #51. Google leads Anthropic by about 16 points, and Argon's ±9 interval overlaps Opus 5.5's. https://arena.ai/leaderboard/text/overall-no-style-control - [2026-10-02] A Manifold market snapshot of the Oct 2 board had Argon at 1525 ±9 on about 4.9k votes, with the next five all Anthropic at 1501–1505. Argon's score has since risen to 1532 with a similar vote count. https://manifold.markets/Terminator2/which-company-will-have-the-1-model - [2026-09-30] Google announced Gemini 4 Argon in a restricted rollout (Fairwind program). Arena put its high-reasoning setting at #1 in Text on 4,942 votes, labelled preliminary. https://www.inkl.com/news/gemini-4-argon-matches-gpt-6-astra-on-key-benchmarks-as-google-restricts-wider-access-to-public - [2026-10-13] Gemini 4 Argon became generally available on the paid API, in the Gemini app and for enterprise. Introductory pricing is $2/$10 per million tokens. https://www.marktechpost.com/2026/10/13/google-gemini-4-argon-api-release/ - [2026-10-13] A secondary source says the $2/$10 pricing runs through Nov 30, then rises to $4/$20. Wider use may bring many more votes, so the preliminary score could move before the Nov 30 check. https://www.lindy.ai/blog/gemini-4-argon-vs-gpt-6-astra - [2026-09-22] Anthropic launched Claude Opus 5.5, which it says performs at the level of Fable 5.1 on most work. Sonnet 5.5 followed on Sep 28 and Haiku 5.5 on Oct 7. Fable 5.1 and Mythos 5.1 launched Sep 1. https://support.claude.com/en/articles/12138966-release-notes and https://hidekazu-konishi.com/entry/anthropic_claude_model_release_timeline.html - [2026-10-13 to 10-15, unconfirmed] There are reports of "Claude Fable 5.5" traces in Azure configs and of apparently better outputs under the Opus 5.5 label. Anthropic has not announced it. The same post says a Polymarket market had about a 94% chance of a Fable release by Oct 31. Rumours also mention an "Opus 6" in November. It also says OpenAI's "Astra 6.1" is rumoured to be close. https://daily.dev/posts/claude-fable-5-5-shows-up-in-azure-configs-as-polymarket-expects-an-october-release-f1hffcfsf - [2026-10-13] The same post cites a Polymarket market on the Oct 31 #1 (a sibling contract, not this one). It had Google at about 66% and Anthropic at about 32%. Treat that as stale. https://daily.dev/posts/claude-fable-5-5-shows-up-in-azure-configs-as-polymarket-expects-an-october-release-f1hffcfsf - [2026-09-03] OpenAI released GPT-6 Astra. On Artificial Analysis, Argon (53) matches Astra (53) and edges GPT-6.1 Sol (52). I did not see Astra on the Arena Text board. A GPT-6.1 Sol variant (gpt-6.1-sol-max) sits at #57 (1448). https://www.lindy.ai/blog/gemini-4-argon-vs-gpt-6-astra and https://www.latent.space/p/ainews-gemini-4-argon-gdms-answer - [2026-09-23] SpaceXAI (xAI) shipped Grok 4.7 on Sep 21. Grok 5 has no confirmed date. https://felloai.com/all-we-know-so-far-about-grok-5/ - [2026-06 to 08] Claude Fable 5 held #1 at about 1508–1525 over the summer, per secondary sources. On 2026-09-02 an aggregator listed Anthropic models at #1–#3. Anthropic has therefore led recently, and Google took #1 only after Argon appeared around Sep 30. https://superpowers-skills.com/en-us/2026/09/02/ai-model-leaderboards-2026.html - [2026-10-15] The board has several Anthropic models bunched at 1502–1516, but the top Anthropic entry is about 16 points behind. The other non-Google labs (Meta 1501, OpenAI, SpaceXAI) are further back. https://arena.ai/leaderboard/text/overall-no-style-control BOTTOM LINE: As of Oct 16, Google leads the resolution board with a preliminary, high-variance Argon score, and Anthropic holds #2–#6 about 16 points back. The main near-term swing is a possible Anthropic Fable 5.5 or Opus 6 release (rumoured, unconfirmed). A GPT-6.x or Gemini update could also move the ranking before the Nov 30 check. NOT FOUND: Any official Anthropic announcement of Fable 5.5 or Opus 6, or a dated release schedule before Nov 30. Any GPT-6 Astra entry on the Arena Text board. Arena's own post on Argon's Text Arena ranking.

- [2026-10-15] The live Arena Text Overall leaderboard (style control off, Oct 15 snapshot, 8.83M votes) has Google's gemini-4-argon-high at #1 with 1532 ±9, marked "Preliminary" on only 4,904 votes. Next is Anthropic's claude-opus-5.5-high at 1516 ±7 (8,300 votes), then claude-fable-5.1-max at 1512 and claude-opus-5-max at 1508. Rank spreads show #1 is 1–1 for Gemini and 2–5 for Opus 5.5. The lead over Anthropic is about 16 points. Meta's muse-wonder-max is #7 at 1501 on 3.2k votes. The best OpenAI model on this page is gpt-5.5-high, around #28 at 1471, and gpt-6.1-sol-max is at 1448. The best xAI (SpaceXAI) model is around #51. https://arena.ai/leaderboard/text/overall-no-style-control - [2026-10-02] Manifold's creator-bot described the Oct 2 board. Argon was #1 at 1525 ±9 on about 4.9k votes, and the next five were all Anthropic models at 1501–1505. The bot argued that new models' scores usually drift down as votes accumulate. It put its own odds for the end of October at Google 50%, Anthropic 32%, OpenAI 13%. The Manifold crowd price was Google 86%, Anthropic 7%. https://manifold.markets/Terminator2/which-company-will-have-the-1-model - [2026-10-13] Secondary report on Polymarket's end-of-October "best model" market: Google 71%, Anthropic 26%. Anthropic had fallen from the 80s and Google had risen from the low 30s. The year-end market was reported at Google 42%, Anthropic 42%, OpenAI 9%. The article says the monthly markets swing 60+ points within days. https://dev.to/max_quimby/the-best-model-race-is-over-heres-what-actually-matters-4ndh - [2026-10-01] Polymarket year-end 2026 market: Anthropic 53%, Google 39.5%, OpenAI 3.5%. The same snapshot lists a Polymarket end-of-November market with Google at 55.5%. This is a sibling contract and the price may be stale. https://polymarkettrader.com/odds/which-company-has-best-ai-model-end-of-2026/ - [2026-09-30] Year-end market history: before a late-September swing, Anthropic was about 74% and Google about 10%. Then Google gained 27 points in a week and Anthropic lost 18, to 56%. The page says Anthropic was #1 at the end of every month from Feb to Aug on Polymarket's settled monthly markets, and Google was #1 at the end of January. https://defirate.com/prediction-markets/best-ai-model-odds-this-year/ - [2026-09-25] Anthropic's claude-opus-5.5-high debuted at #1 with 1509 on only 2,307 votes, ahead of Gemini 3.8 Flash at 1492. It has since risen to 1516 with more votes. A Sept 2 snapshot had claude-fable-5 at #1 with 1508. https://neuraltrust.ai/blog/claude-opus-5-5-vs-gemini-benchmark - [2026-10-15] On the live board, Anthropic holds 5 of the top 6 spots, and 5 of the top 10 including #2 through #6. So if Argon's score decays, Anthropic is the likeliest successor. The top Anthropic scores of 1516, 1512 and 1508 sit within about 8 points of each other. https://arena.ai/leaderboard/text/overall-no-style-control - [2025-11-30] Polymarket's end-of-November 2025 "best model" market ended with Google 100%. Polymarket's own page quotes a 94% one-month accuracy for its markets. https://polymarket.com/event/which-company-has-best-ai-model-end-of-november - [2026-03-31] Reference class: Arena posted that Claude Opus 4.6 models "remained on top" through March 2026. Anthropic held #1 from about February through August 2026, roughly six or more consecutive monthly resolutions. The #1 slot changed hands only when a new flagship launched: Gemini in late 2025, Anthropic in February 2026, and Google's Argon in late September 2026. https://x.com/arena/status/2039081680515011022 - [2026-10-15] Upcoming catalysts: Meta's muse-wonder launched Oct 13 and is #7. GPT-6 Astra is reported at about #26 (1478) as of late September. A Gemini 3.5 Pro was mentioned as pending in a September article, but Argon already leads. No Anthropic release between Oct 15 and Nov 30 was found. https://dev.to/max_quimby/the-best-model-race-is-over-heres-what-actually-matters-4ndh BOTTOM LINE: On base rates, the #1 slot has been sticky between flagship releases. Anthropic held it for about six months, and Google took it in late September with a preliminary, high-variance 16-point lead that may shrink as votes come in. Markets in early to mid October were roughly split between Google and Anthropic for year-end, with Google ahead for the end-of-October and end-of-November markets. Anthropic's deep bench of #2–#6 models makes it the main fallback. NOT FOUND: The live price of the target end-of-November contract (deliberately not searched for). Any official Anthropic or Google release schedule for November 2026. Arena's historical score-decay data for new models. A verified current Polymarket page for the end-of-November 2026 market. The figures above on it come from secondary sites.

YES means: Anthropic owns the model ranked #1 on the arena.ai Text Arena (Overall, style control off) when it is checked on Nov 30, 2026, 12:00 PM ET. - [2026-10-15] Arena's changelog shows no new Text Arena entry for a model above Opus 5.5 since Argon was added on Sep 30. Between Oct 2 and Oct 15 the changelog adds only Sonnet 5.5, Mistral Large 4 and Muse Spark 1.3 to the Text board. Argon's lead therefore rests on the same ~4.9k votes it had on Sep 30–Oct 2. https://arena.ai/company/leaderboard-changelog - [2026-10-02] Argon's Arena score was 1525 on 4,932 votes. The 20-point gap it showed was against Opus 4.6 (1505). Arena's own tweet framed it against Opus 4.6, not Opus 5.5. Argon's Math tag was based on only 255 votes. Every Argon Arena rating carried the "Preliminary" tag. https://dev.to/eristoddle/gemini-4-argon-won-every-arena-category-you-cant-use-it-4fc9 - [2026-10-02] Argon's vote base is small next to the models it displaced. Opus 4.6 had 77,636 Overall votes against Argon's ~4.9k. A thin sample plus a ±9 interval is the mechanism for the gap closing. Anthropic's Opus 5.5 is already at 1516 on 8.3k votes. https://dev.to/eristoddle/gemini-4-argon-won-every-arena-category-you-cant-use-it-4fc9 - [2026-10-13] Argon moved from a restricted rollout to general availability on the paid API, and Argon had the Sep 30–Oct 2 votes only from early access. Broader, less self-selected prompt traffic is the likeliest source of score regression. Anthropic's Opus 5.5 is already priced at $4/$20, double Argon's intro price. https://www.marktechpost.com/2026/10/13/google-gemini-4-argon-api-release/ - [2026-10-11] Several X accounts report some Opus 5.5 requests routed to a newer, unnamed model. Guesses are Fable 5.5, Opus 5.6 or Opus 6. One earlier Opus 5.2 routing rumour ended with Anthropic shipping Opus 5.5 on Sep 22. Fable 5.5 routing reports on Oct 1–2 produced no release. No post shows a model ID. https://cellcog.ai/blog/claude-opus-5-6-release-date/ - [2026-10-13] A claude-fable-5-5 identifier appeared in Azure's catalog and was synced into LiteLLM. Its specs were copied from Fable 5.1, so they read as placeholders. Anthropic's docs list no Fable 5.5. This is a prerequisite signal for the main YES path, a new Anthropic flagship, and it is not confirmation. https://cellcog.ai/blog/fable-5-5-release-date/ - [2026-10-15] Kalshi's Opus 6 release market (snapshot ~Oct 9) priced release before Nov 16 at 12% and before Dec 1 at 17%. That is a sibling market, not this one. It implies a named Opus 6 is a minority outcome, but a Fable 5.5 or Opus 5.6 point release is a separate and likelier path. https://kalshi.com/markets/kxclaude/claude-model-release/kxclaude-opus6 - [2026-10-14] Prior cadence: Opus 4.6 on Feb 5, Opus 4.7 on Apr 16, Opus 4.8 on May 28, Fable 5 on Jun 9, Fable 5.1 on Sep 1, Opus 5.5 on Sep 22, Haiku 5.5 on Oct 7. That is a roughly 2–10 week flagship rhythm. A Fable 5.5 or Opus 5.6 in Oct 16–Nov 24 would fit it. Opus 4.5 shipped Nov 24, 2025, so late-November launches have precedent. Whether a launch lands on the board before the Nov 30 check is unknown. https://github.com/jqueryscript/anthropic-claude-timeline - [2026-08] Precedent for Anthropic recovering #1 via vote accumulation. Claude Fable 5 was restored on Jul 1, Arena re-baselined its score on Jul 12, and it settled back at #1 at ~1525. Arena's re-baselining shows scores can move materially once votes accrue. https://localaimaster.com/blog/lmarena-chatbot-arena-leaderboard - [2026-09-02] Before Argon, the Anthropic bench was deep. Claude-fable-5-high was #1 at 1506±5 on 30,057 votes. Anthropic then held the top positions through Sep 25, when Opus 5.5 debuted at #1. The top Anthropic models are within ~8 points of one another, so any of three can take #1 if Argon fades by ~16 points. Argon's ±9 interval touches Opus 5.5's ±7 interval. https://www.stephanmiller.com/track-new-ai-models-on-the-arena-leaderboard/ - [2026-10-02] On independent evals Argon is not dominant. Artificial Analysis puts Argon at 53 and 8th. Opus 5.5 scores 58 and Sonnet 5.5 scores 56. Arena's human-preference lead for Argon is therefore not matched by expert-style benchmarks, which suggests the gap may be partly a style-driven, early-vote effect. https://emergent.sh/learn/gemini-4-argon-benchmarks - [2026-10-15] The rival field is weak this late in the window. OpenAI's best Text entry is ~1471, and the Oct 7–8 GPT-6 tier launches have no Text entry above Argon. A rumoured "Bell" model is unconfirmed. So this is a Google-vs-Anthropic question unless OpenAI ships something unexpected. https://shattered.io/claude-opus-6-rumors-opus-5-5-cost-cut-2026/ BOTTOM LINE: The strongest YES path is that Argon's thin, preliminary 1532 settles about 10–20 points lower as GA traffic brings votes, which would put a top Anthropic entry (Opus 5.5 at 1516, or Fable 5.1) back at #1. A new Anthropic flagship (Fable 5.5 or Opus 5.6) reaching the board before Nov 30 would reinforce this. The flagship release is rumoured and unconfirmed, so the main prerequisite is score regression for Argon. NOT FOUND: Any official Anthropic announcement of Fable 5.5 or Opus 5.6 or Opus 6, or a release date. Arena's historical decay data for preliminary scores. Argon's current Overall vote count after GA. Confirmation of the Azure Fable 5.5 identifier working.

YES means: Anthropic owns the model in first place (by Arena rank, then score) on the arena.ai Text Arena Overall board (style control off, "Models" filter, AutoEval excluded) when checked on 2026-11-30 at 12:00 PM ET. - [2026-10-16] The live board (fetched, dated Oct 15, 416 models) shows Anthropic is not #1 and has no tie for rank 1. Argon's rank spread is 1–1, so the Argon-vs-Anthropic gap is already at the rank level. Opus 5.5's spread is 2–5, and every other Anthropic entry has a lower bound of 2 or worse. Anthropic's tiebreak route (alphabetical order, or a higher unrounded score) only opens if Argon's rank slips to a shared 1. The Oct 15 gap is 1532 vs 1516. https://arena.ai/leaderboard/text/overall-no-style-control - [2026-10-16] The Sept–Oct "Argon will decay" thesis has not shown up in the data. Arena's Sep 30 post had Argon at 1525. The Oct 15 board has it at 1532 on roughly the same ~4.9k votes. The Oct 2 snapshot had it at 1525 on 4,932 votes. So the score rose about 7 points over two weeks. https://x.com/arena/status/2105394855644139908 and https://dev.to/eristoddle/gemini-4-argon-won-every-arena-category-you-cant-use-it-4fc9 - [2026-10-15] Argon's vote count barely moved between Oct 2 and Oct 15 (4,932 to 4,904). Its reported lead is therefore not a thin-sample artefact that more votes would obviously erase. It also leads the Coding, Hard Prompts, Instruction Following, Longer Query, Creative Writing, English, non-English and occupational sub-boards. A lead across categories suggests broad preference, not one niche. Arena listed all of these as preliminary on Sep 30. https://x.com/arena/status/2105394855644139908 - [2026-10-15] Anthropic's own newest flagship is not clearly above its older ones on this board. The board has Opus 5.5 (1516) ahead of Fable 5.1 (1512), and Anthropic's own materials position Opus 5.5 at Fable level. A rumoured "Fable 5.5" therefore has to beat Opus 5.5 by more than 16 points to take #1. Anthropic's recent top-end steps have been about 4–13 points. Opus 5 was 1503 and Opus 5.5 is 1516, and Opus 5.5 debuted at 1509 on Sep 25. https://arena.ai/leaderboard/text/overall-no-style-control and https://emergent.sh/news/claude-fable-5-5-release-date - [2026-10-16] The Fable 5.5 evidence is thin. The Oct 13 Azure/LiteLLM entry has every spec copied from Fable 5.1, so it reads as a placeholder. The Sep 22 Opus 5.5 announcement named only Sonnet and Haiku as follow-ups, not a Fable. As of Oct 13 there is no Anthropic announcement, model card or price. One report cites an X-sourced November release near an IPO; it has no official source. I found no Opus 6 date. https://cellcog.ai/blog/fable-5-5-release-date/ and https://cryptobriefing.com/claude-fable-5-5-azure-sighting/ - [2026-10-16] Deadline arithmetic: about 45 days remain. A release would also need to land with enough Arena votes to be ranked, and new models post preliminary scores for days to weeks. Opus 5.5 reached #1 on 2,307 votes within 3 days of launch, so ranking is fast. But a late-November launch gives less time for the score to settle upward. The Arena changelog through Oct 15 lists no new Anthropic Text entries since Opus 5.5, only Haiku 5.5 on Agent Arena. https://arena.ai/company/leaderboard-changelog and https://neuraltrust.ai/blog/claude-opus-5-vs-gemini-benchmark - [2026-10-13] Argon's wider availability makes its lead more likely to hold. It became generally available on Oct 13 at an introductory $2/$10 through Nov 30, undercutting Opus 5.5 ($4/$20) and Fable 5.1 ($10/$50). Cheap, broad access should raise vote volume and narrow its ±9 interval, which is the opposite of a gated-access artefact. The price rise to $4/$20 only starts after the Nov 30 check. https://felloai.com/gemini-4-argon/ and https://arena.ai/leaderboard/text/overall-no-style-control - [2026-10-15] Google has more than one route to #1. Gemini 3.8 Flash (1499, preliminary) already sits at #8. Arena's Sep 30 post called Argon a big jump from 3.8 Flash. Any further Google update (a Pro tier or an Argon variant) would extend a lead Anthropic has to overcome. Other labs also threaten to split Anthropic's chances. Meta's muse-wonder-max (1501) has a rank spread of 2–15 on only 3.2k votes. The Arena homepage banner on Oct 15 listed Muse Wonder as "#2 in Text", though that view may use a different default. This is a further reason Anthropic isn't a safe default #2. https://arena.ai/leaderboard - [2026-10-16] Resolution technicalities favour the incumbent. The market reads the "Rank" column with style control off and the "Models" filter. Ranks come from confidence intervals, and ties are broken by unrounded score. Anthropic's four top models overlap in rank, but rank 1 is held solely by Argon. Because Argon's rank spread is 1–1, a score tie would be needed to trigger the alphabetical rule. Anthropic would be ahead of Google only on exact score equality, which is negligible. Arena currently lists Argon with a Preliminary tag, but the rules exclude only "AutoEval" models, not Preliminary ones. https://arena.ai/leaderboard/text/overall-no-style-control - [2026-10-12] Arena's Oct 12 funding news and the new Alignment Index put GPT-6.1 Sol on top of Arena's alignment ranking and say Arena is testing GPT-6.1. This is not the Text board. It does signal Arena is actively adding OpenAI models to Text with scores to follow. If GPT-6.1 or Astra enters above 1532, that could also take #1 from both Google and Anthropic. Best OpenAI Text entries now are #28 (gpt-5.5-high, 1471) and #57 (gpt-6.1-sol-max, 1448). https://theaiinsider.tech/2026/10/12/arena-secures-200m-series-b-at-3-1b-valuation-and-adds-ai-alignment-leaderboard/ and https://digg.com/ai/zr97dlv8 - [2025-11-30] Precedent for "Google leading late in the year": the end-of-November 2025 Polymarket market resolved Google at 100%. Polymarket's page notes a 94% one-month accuracy for its markets. This is the same contract family, not this one. Google held #1 around the last two year-ends. https://polymarket.com/event/which-company-has-best-ai-model-end-of-november BOTTOM LINE: Anthropic has to climb 16 points, or wait for Argon to fall, in about 45 days, and the Argon score has risen rather than decayed since Oct 2. The Fable 5.5 and Opus 6 rumours rest on placeholder catalog entries with no announcement or date, and Anthropic's own flagship steps have been smaller than the gap. Meanwhile Google (Argon, 3.8 Flash line) and OpenAI/Meta entries add other paths to a non-Anthropic #1. NOT FOUND: Any Anthropic announcement, model card or dated release plan for Fable 5.5 or Opus 6. Historical data on how much Arena preliminary scores drift after launch. Any GPT-6 Astra or GPT-6.1 Sol Text entry above 1448. Any Google statement on a post-Argon Text model before Nov 30.