OpenAI’s GPT-6 Astra launch on September 3 quickly claimed the top spot on the Code Arena WebDev leaderboard with 1,797 points, ahead of Anthropic’s Claude Fable 5.1 at roughly 1,762–1,763 and Claude Opus 5 at 1,688. This recent shift has solidified OpenAI’s lead in the crowdsourced Elo-style ranking focused on agentic frontend tasks, multi-step reasoning, and tool use. Anthropic nonetheless retains a strong implied probability as second-best lab through its sustained performance on SWE-bench Verified (Opus 5 at 97%), CursorBench, and internal production coding metrics, where its models have long demonstrated reliable long-horizon agentic capabilities. With end-of-September resolution approaching, traders are weighing whether OpenAI’s momentum holds or if Anthropic’s coding depth and recent model releases allow it to close the narrow gap.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedAnthropic 75.1%
OpenAI 15.4%
Alibaba 5%
SpaceXAI 3.3%
$59,898 Vol.
$59,898 Vol.
Sep 30, 2026
Anthropic
75%
OpenAI
15%
Alibaba
5%
SpaceXAI
3%
Moonshot
3%
Tencent
1%
ByteDance
1%
Z.ai
<1%
Meta
<1%
<1%
MiniMax
<1%
Xiaomi
<1%
DeepSeek
<1%
Thinky
<1%
Poolside
<1%
Mistral
<1%
Anthropic 75.1%
OpenAI 15.4%
Alibaba 5%
SpaceXAI 3.3%
$59,898 Vol.
$59,898 Vol.
Sep 30, 2026
Anthropic
$10,613 Vol.
75%
OpenAI
$5,357 Vol.
15%
Alibaba
$16,293 Vol.
5%
SpaceXAI
$1,924 Vol.
3%
Moonshot
$11,703 Vol.
3%
Tencent
$1,356 Vol.
1%
ByteDance
$2,799 Vol.
1%
Z.ai
$1,364 Vol.
<1%
Meta
$1,283 Vol.
<1%
$1,336 Vol.
<1%
MiniMax
$598 Vol.
<1%
Xiaomi
$1,468 Vol.
<1%
DeepSeek
$1,022 Vol.
<1%
Thinky
$617 Vol.
<1%
Poolside
$1,035 Vol.
<1%
Mistral
$1,130 Vol.
<1%
This market will resolve according to the second-highest ranked Company based on the arena.ai Code Arena | WebDev Leaderboard when the table under "Code Arena | WebDev" filtered for "Labs" is checked on September 30, 2026, 12:00 PM ET.
Results from the "Lab Rank" column under the "Code Arena | WebDev" Leaderboard tab at https://arena.ai/leaderboard/code/webdev?rankBy=labs (Overall) filtered for "Labs" will be used to resolve this market.
AI companies will be ordered primarily by their Lab Rank at the market’s check time. If the results based on the lab ranking are ambiguous or unavailable, the relevant AI companies will be ordered according to their highest-ranking AI model in the leaderboard’s “Models” view. If two or more models are tied on rank, they will be ordered by which model is listed higher on the leaderboard. If a tie still remains, alphabetical order of AI lab/company names as listed in this market group will be used as a final tiebreaker (e.g., “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies second place under this ranking.
The resolution source for this market is the arena.ai Code Arena | WebDev Leaderboard. 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".OpenAI’s GPT-6 Astra launch on September 3 quickly claimed the top spot on the Code Arena WebDev leaderboard with 1,797 points, ahead of Anthropic’s Claude Fable 5.1 at roughly 1,762–1,763 and Claude Opus 5 at 1,688. This recent shift has solidified OpenAI’s lead in the crowdsourced Elo-style ranking focused on agentic frontend tasks, multi-step reasoning, and tool use. Anthropic nonetheless retains a strong implied probability as second-best lab through its sustained performance on SWE-bench Verified (Opus 5 at 97%), CursorBench, and internal production coding metrics, where its models have long demonstrated reliable long-horizon agentic capabilities. With end-of-September resolution approaching, traders are weighing whether OpenAI’s momentum holds or if Anthropic’s coding depth and recent model releases allow it to close the narrow gap.
This market will resolve according to the second-highest ranked Company based on the arena.ai Code Arena | WebDev Leaderboard when the table under "Code Arena | WebDev" filtered for "Labs" is checked on September 30, 2026, 12:00 PM ET.
Results from the "Lab Rank" column under the "Code Arena | WebDev" Leaderboard tab at https://arena.ai/leaderboard/code/webdev?rankBy=labs (Overall) filtered for "Labs" will be used to resolve this market.
AI companies will be ordered primarily by their Lab Rank at the market’s check time. If the results based on the lab ranking are ambiguous or unavailable, the relevant AI companies will be ordered according to their highest-ranking AI model in the leaderboard’s “Models” view. If two or more models are tied on rank, they will be ordered by which model is listed higher on the leaderboard. If a tie still remains, alphabetical order of AI lab/company names as listed in this market group will be used as a final tiebreaker (e.g., “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies second place under this ranking.
The resolution source for this market is the arena.ai Code Arena | WebDev Leaderboard. 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 "Lab Rank" column under the "Code Arena | WebDev" Leaderboard tab at https://arena.ai/leaderboard/code/webdev?rankBy=labs (Overall) filtered for "Labs" will be used to resolve this market.
AI companies will be ordered primarily by their Lab Rank at the market’s check time. If the results based on the lab ranking are ambiguous or unavailable, the relevant AI companies will be ordered according to their highest-ranking AI model in the leaderboard’s “Models” view. If two or more models are tied on rank, they will be ordered by which model is listed higher on the leaderboard. If a tie still remains, alphabetical order of AI lab/company names as listed in this market group will be used as a final tiebreaker (e.g., “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies second place under this ranking.
The resolution source for this market is the arena.ai Code Arena | WebDev Leaderboard. 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 24, 2026, 7:45 PM ET
Volume
$59,898End Date
Oct 1, 2026Market Opened
Jul 24, 2026, 7:45 PM ETResolution Source
https://arena.ai/leaderboard/code/webdev?rankBy=labsResolver
0x69c47De9D...This market will resolve according to the second-highest ranked Company based on the arena.ai Code Arena | WebDev Leaderboard when the table under "Code Arena | WebDev" filtered for "Labs" is checked on September 30, 2026, 12:00 PM ET.
Results from the "Lab Rank" column under the "Code Arena | WebDev" Leaderboard tab at https://arena.ai/leaderboard/code/webdev?rankBy=labs (Overall) filtered for "Labs" will be used to resolve this market.
AI companies will be ordered primarily by their Lab Rank at the market’s check time. If the results based on the lab ranking are ambiguous or unavailable, the relevant AI companies will be ordered according to their highest-ranking AI model in the leaderboard’s “Models” view. If two or more models are tied on rank, they will be ordered by which model is listed higher on the leaderboard. If a tie still remains, alphabetical order of AI lab/company names as listed in this market group will be used as a final tiebreaker (e.g., “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies second place under this ranking.
The resolution source for this market is the arena.ai Code Arena | WebDev Leaderboard. 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".OpenAI’s GPT-6 Astra launch on September 3 quickly claimed the top spot on the Code Arena WebDev leaderboard with 1,797 points, ahead of Anthropic’s Claude Fable 5.1 at roughly 1,762–1,763 and Claude Opus 5 at 1,688. This recent shift has solidified OpenAI’s lead in the crowdsourced Elo-style ranking focused on agentic frontend tasks, multi-step reasoning, and tool use. Anthropic nonetheless retains a strong implied probability as second-best lab through its sustained performance on SWE-bench Verified (Opus 5 at 97%), CursorBench, and internal production coding metrics, where its models have long demonstrated reliable long-horizon agentic capabilities. With end-of-September resolution approaching, traders are weighing whether OpenAI’s momentum holds or if Anthropic’s coding depth and recent model releases allow it to close the narrow gap.
This market will resolve according to the second-highest ranked Company based on the arena.ai Code Arena | WebDev Leaderboard when the table under "Code Arena | WebDev" filtered for "Labs" is checked on September 30, 2026, 12:00 PM ET.
Results from the "Lab Rank" column under the "Code Arena | WebDev" Leaderboard tab at https://arena.ai/leaderboard/code/webdev?rankBy=labs (Overall) filtered for "Labs" will be used to resolve this market.
AI companies will be ordered primarily by their Lab Rank at the market’s check time. If the results based on the lab ranking are ambiguous or unavailable, the relevant AI companies will be ordered according to their highest-ranking AI model in the leaderboard’s “Models” view. If two or more models are tied on rank, they will be ordered by which model is listed higher on the leaderboard. If a tie still remains, alphabetical order of AI lab/company names as listed in this market group will be used as a final tiebreaker (e.g., “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies second place under this ranking.
The resolution source for this market is the arena.ai Code Arena | WebDev Leaderboard. 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 "Lab Rank" column under the "Code Arena | WebDev" Leaderboard tab at https://arena.ai/leaderboard/code/webdev?rankBy=labs (Overall) filtered for "Labs" will be used to resolve this market.
AI companies will be ordered primarily by their Lab Rank at the market’s check time. If the results based on the lab ranking are ambiguous or unavailable, the relevant AI companies will be ordered according to their highest-ranking AI model in the leaderboard’s “Models” view. If two or more models are tied on rank, they will be ordered by which model is listed higher on the leaderboard. If a tie still remains, alphabetical order of AI lab/company names as listed in this market group will be used as a final tiebreaker (e.g., “Google” would be ranked ahead of “SpaceXAI”). This market will resolve based on the company that occupies second place under this ranking.
The resolution source for this market is the arena.ai Code Arena | WebDev Leaderboard. 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
$59,898End Date
Oct 1, 2026Market Opened
Jul 24, 2026, 7:45 PM ETResolution Source
https://arena.ai/leaderboard/code/webdev?rankBy=labsResolver
0x69c47De9D...OpenAI’s GPT-6 Astra launch on September 3 quickly claimed the top spot on the Code Arena WebDev leaderboard with 1,797 points, ahead of Anthropic’s Claude Fable 5.1 at roughly 1,762–1,763 and Claude Opus 5 at 1,688. This recent shift has solidified OpenAI’s lead in the crowdsourced Elo-style ranking focused on agentic frontend tasks, multi-step reasoning, and tool use. Anthropic nonetheless retains a strong implied probability as second-best lab through its sustained performance on SWE-bench Verified (Opus 5 at 97%), CursorBench, and internal production coding metrics, where its models have long demonstrated reliable long-horizon agentic capabilities. With end-of-September resolution approaching, traders are weighing whether OpenAI’s momentum holds or if Anthropic’s coding depth and recent model releases allow it to close the narrow gap.
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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