Anthropic’s Claude Mythos 5, Opus 5, and Fable 5 models currently top multiple independent leaderboards for quality, coding, and agentic reasoning as of mid-August 2026, driving the market’s strong 80.5% implied probability for the company to hold the #1 position by end of September. These releases extended Anthropic’s edge on benchmarks such as SWE-bench Verified, GPQA, and composite indices while maintaining 1M-token context and competitive pricing, outpacing OpenAI’s GPT-5 variants and Google’s Gemini 3 family despite their multimodal and search strengths. With only six weeks until resolution, traders see limited near-term catalysts from rivals capable of shifting the ranking, though any surprise model drop or benchmark reversal could still alter outcomes. The odds aggregate skin-in-the-game sentiment favoring Anthropic’s consistent frontier performance and developer ecosystem momentum.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedAnthropic 81%
Google 6.0%
OpenAI 5.2%
StepFun 4.6%
$26,148 Vol.
$26,148 Vol.
Sep 30, 2026
Anthropic
81%
6%
OpenAI
5%
StepFun
5%
Alibaba
5%
Thinky
3%
DeepSeek
3%
Z.ai
3%
Moonshot
3%
Meituan
3%
Xiaomi
3%
Baidu
3%
Nvidia
2%
Mistral
2%
Meta
1%
Tencent
1%
Microsoft
1%
ByteDance
1%
MiniMax
1%
Amazon
1%
SpaceXAI
<1%
Anthropic 81%
Google 6.0%
OpenAI 5.2%
StepFun 4.6%
$26,148 Vol.
$26,148 Vol.
Sep 30, 2026
Anthropic
$19,440 Vol.
81%
$495 Vol.
6%
OpenAI
$424 Vol.
5%
StepFun
$277 Vol.
5%
Alibaba
$453 Vol.
5%
Thinky
$200 Vol.
3%
DeepSeek
$200 Vol.
3%
Z.ai
$200 Vol.
3%
Moonshot
$270 Vol.
3%
Meituan
$257 Vol.
3%
Xiaomi
$288 Vol.
3%
Baidu
$244 Vol.
3%
Nvidia
$250 Vol.
2%
Mistral
$249 Vol.
2%
Meta
$385 Vol.
1%
Tencent
$1,069 Vol.
1%
Microsoft
$391 Vol.
1%
ByteDance
$229 Vol.
1%
MiniMax
$229 Vol.
1%
Amazon
$229 Vol.
1%
SpaceXAI
$369 Vol.
<1%
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) (Style Control On) 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 with style control on (Adjustments: Style Control) 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".Anthropic’s Claude Mythos 5, Opus 5, and Fable 5 models currently top multiple independent leaderboards for quality, coding, and agentic reasoning as of mid-August 2026, driving the market’s strong 80.5% implied probability for the company to hold the #1 position by end of September. These releases extended Anthropic’s edge on benchmarks such as SWE-bench Verified, GPQA, and composite indices while maintaining 1M-token context and competitive pricing, outpacing OpenAI’s GPT-5 variants and Google’s Gemini 3 family despite their multimodal and search strengths. With only six weeks until resolution, traders see limited near-term catalysts from rivals capable of shifting the ranking, though any surprise model drop or benchmark reversal could still alter outcomes. The odds aggregate skin-in-the-game sentiment favoring Anthropic’s consistent frontier performance and developer ecosystem momentum.
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) (Style Control On) 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 with style control on (Adjustments: Style Control) 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".
Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall with style control on (Adjustments: Style Control) 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".
Market Opened: Jul 20, 2026, 8:32 PM ET
Volume
$26,148End Date
Sep 30, 2026Market Opened
Jul 20, 2026, 8:32 PM ETResolution Source
https://arena.ai/leaderboard/text/overallResolver
0x69c47De9D...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) (Style Control On) 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 with style control on (Adjustments: Style Control) 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".Anthropic’s Claude Mythos 5, Opus 5, and Fable 5 models currently top multiple independent leaderboards for quality, coding, and agentic reasoning as of mid-August 2026, driving the market’s strong 80.5% implied probability for the company to hold the #1 position by end of September. These releases extended Anthropic’s edge on benchmarks such as SWE-bench Verified, GPQA, and composite indices while maintaining 1M-token context and competitive pricing, outpacing OpenAI’s GPT-5 variants and Google’s Gemini 3 family despite their multimodal and search strengths. With only six weeks until resolution, traders see limited near-term catalysts from rivals capable of shifting the ranking, though any surprise model drop or benchmark reversal could still alter outcomes. The odds aggregate skin-in-the-game sentiment favoring Anthropic’s consistent frontier performance and developer ecosystem momentum.
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) (Style Control On) 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 with style control on (Adjustments: Style Control) 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".
Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall with style control on (Adjustments: Style Control) 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".
Volume
$26,148End Date
Sep 30, 2026Market Opened
Jul 20, 2026, 8:32 PM ETResolution Source
https://arena.ai/leaderboard/text/overallResolver
0x69c47De9D...Anthropic’s Claude Mythos 5, Opus 5, and Fable 5 models currently top multiple independent leaderboards for quality, coding, and agentic reasoning as of mid-August 2026, driving the market’s strong 80.5% implied probability for the company to hold the #1 position by end of September. These releases extended Anthropic’s edge on benchmarks such as SWE-bench Verified, GPQA, and composite indices while maintaining 1M-token context and competitive pricing, outpacing OpenAI’s GPT-5 variants and Google’s Gemini 3 family despite their multimodal and search strengths. With only six weeks until resolution, traders see limited near-term catalysts from rivals capable of shifting the ranking, though any surprise model drop or benchmark reversal could still alter outcomes. The odds aggregate skin-in-the-game sentiment favoring Anthropic’s consistent frontier performance and developer ecosystem momentum.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
Beware of external links.
Beware of external links.
Frequently Asked Questions