Anthropic’s September 1 release of Claude Fable 5.1 Max has anchored trader sentiment, delivering measurable gains on coding, agentic, and long-horizon benchmarks such as Terminal-Bench and Frontier-Bench while cutting effective cost through lower-effort modes and cheaper cache reads. The model tops recent independent leaderboards and is positioned as the public-facing flagship above the earlier Opus 5 tier. OpenAI’s near-simultaneous GPT-6 Astra launch, which claims leadership in software engineering and cybersecurity, accounts for most of the 42 percent “Other” probability and keeps the race contested ahead of the September 21 snapshot. Lower-priced Opus 5 variants trail because they predate these frontier updates and show narrower margins on the same evaluations.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updatedclaude-fable-5.1-max 55%
Other 42%
claude-opus-5-high 3.5%
claude-opus-5-max 3.1%
NEW
NEW
Sep 21, 2026
claude-fable-5.1-max
55%
Other
42%
claude-opus-5-high
4%
claude-opus-5-max
3%
claude-opus-4-6-high
1%
claude-fable-5.1-max 55%
Other 42%
claude-opus-5-high 3.5%
claude-opus-5-max 3.1%
NEW
NEW
Sep 21, 2026
claude-fable-5.1-max
$2,536 Vol.
55%
Other
$1,943 Vol.
42%
claude-opus-5-high
$128 Vol.
4%
claude-opus-5-max
$319 Vol.
3%
claude-opus-4-6-high
$237 Vol.
1%
This market will resolve according to the model that has the highest arena rank based on the arena.ai Text Arena (Overall) when the table under the "Leaderboard" tab is checked on the specified date, 12:00 PM ET.
Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market.
Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score.
No new model will be added to this market after market creation. Any model not explicitly listed in this market will be encompassed under the "Other" option.
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 model names as listed in this market group (full string, including suffixes such as “-high” and “-max”) will be used as a final tiebreaker (e.g., if two models remain tied, “claude-opus-5-high” would be ranked ahead of “claude-opus-5-max”). This market will resolve to the model that comes first according to this order.
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 September 1 release of Claude Fable 5.1 Max has anchored trader sentiment, delivering measurable gains on coding, agentic, and long-horizon benchmarks such as Terminal-Bench and Frontier-Bench while cutting effective cost through lower-effort modes and cheaper cache reads. The model tops recent independent leaderboards and is positioned as the public-facing flagship above the earlier Opus 5 tier. OpenAI’s near-simultaneous GPT-6 Astra launch, which claims leadership in software engineering and cybersecurity, accounts for most of the 42 percent “Other” probability and keeps the race contested ahead of the September 21 snapshot. Lower-priced Opus 5 variants trail because they predate these frontier updates and show narrower margins on the same evaluations.
This market will resolve according to the model that has the highest arena rank based on the arena.ai Text Arena (Overall) when the table under the "Leaderboard" tab is checked on the specified date, 12:00 PM ET.
Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market.
Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score.
No new model will be added to this market after market creation. Any model not explicitly listed in this market will be encompassed under the "Other" option.
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 model names as listed in this market group (full string, including suffixes such as “-high” and “-max”) will be used as a final tiebreaker (e.g., if two models remain tied, “claude-opus-5-high” would be ranked ahead of “claude-opus-5-max”). This market will resolve to the model that comes first according to this order.
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-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market.
Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score.
No new model will be added to this market after market creation. Any model not explicitly listed in this market will be encompassed under the "Other" option.
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 model names as listed in this market group (full string, including suffixes such as “-high” and “-max”) will be used as a final tiebreaker (e.g., if two models remain tied, “claude-opus-5-high” would be ranked ahead of “claude-opus-5-max”). This market will resolve to the model that comes first according to this order.
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: Sep 3, 2026, 10:16 AM ET
Volume
$5,164End Date
Sep 21, 2026Market Opened
Sep 3, 2026, 10:16 AM ETResolver
0x69c47De9D...This market will resolve according to the model that has the highest arena rank based on the arena.ai Text Arena (Overall) when the table under the "Leaderboard" tab is checked on the specified date, 12:00 PM ET.
Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market.
Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score.
No new model will be added to this market after market creation. Any model not explicitly listed in this market will be encompassed under the "Other" option.
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 model names as listed in this market group (full string, including suffixes such as “-high” and “-max”) will be used as a final tiebreaker (e.g., if two models remain tied, “claude-opus-5-high” would be ranked ahead of “claude-opus-5-max”). This market will resolve to the model that comes first according to this order.
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 September 1 release of Claude Fable 5.1 Max has anchored trader sentiment, delivering measurable gains on coding, agentic, and long-horizon benchmarks such as Terminal-Bench and Frontier-Bench while cutting effective cost through lower-effort modes and cheaper cache reads. The model tops recent independent leaderboards and is positioned as the public-facing flagship above the earlier Opus 5 tier. OpenAI’s near-simultaneous GPT-6 Astra launch, which claims leadership in software engineering and cybersecurity, accounts for most of the 42 percent “Other” probability and keeps the race contested ahead of the September 21 snapshot. Lower-priced Opus 5 variants trail because they predate these frontier updates and show narrower margins on the same evaluations.
This market will resolve according to the model that has the highest arena rank based on the arena.ai Text Arena (Overall) when the table under the "Leaderboard" tab is checked on the specified date, 12:00 PM ET.
Results from the "Rank" column under the "Text Arena | Overall" Leaderboard tab at https://arena.ai/leaderboard/text/overall-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market.
Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score.
No new model will be added to this market after market creation. Any model not explicitly listed in this market will be encompassed under the "Other" option.
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 model names as listed in this market group (full string, including suffixes such as “-high” and “-max”) will be used as a final tiebreaker (e.g., if two models remain tied, “claude-opus-5-high” would be ranked ahead of “claude-opus-5-max”). This market will resolve to the model that comes first according to this order.
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-no-style-control with style control off (Adjustments: None) and filtered for "Models" will be used to resolve this market.
Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score.
No new model will be added to this market after market creation. Any model not explicitly listed in this market will be encompassed under the "Other" option.
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 model names as listed in this market group (full string, including suffixes such as “-high” and “-max”) will be used as a final tiebreaker (e.g., if two models remain tied, “claude-opus-5-high” would be ranked ahead of “claude-opus-5-max”). This market will resolve to the model that comes first according to this order.
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
$5,164End Date
Sep 21, 2026Market Opened
Sep 3, 2026, 10:16 AM ETResolver
0x69c47De9D...Anthropic’s September 1 release of Claude Fable 5.1 Max has anchored trader sentiment, delivering measurable gains on coding, agentic, and long-horizon benchmarks such as Terminal-Bench and Frontier-Bench while cutting effective cost through lower-effort modes and cheaper cache reads. The model tops recent independent leaderboards and is positioned as the public-facing flagship above the earlier Opus 5 tier. OpenAI’s near-simultaneous GPT-6 Astra launch, which claims leadership in software engineering and cybersecurity, accounts for most of the 42 percent “Other” probability and keeps the race contested ahead of the September 21 snapshot. Lower-priced Opus 5 variants trail because they predate these frontier updates and show narrower margins on the same evaluations.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
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