The Prediction Markets

Second-best Code Arena WebDev AI Lab end of October?

Closes
Oct 31, 2026, in 8 days
Traded
$48K
Venues
Polymarket
Prices updated
1 min ago
Share

What the markets expect

OpenAI 84.5%

Next is Anthropic at 5.3%. Only Polymarket lists this market, so there is no second price to compare.

OpenAI 84.5%Anthropic 5.3%Meta 4.2%Z.ai 1.5%Google 1.1%11 others 3.4%

Odds by venue

Fair chance strips out each venue’s built-in margin (its prices add up to more than 100%), then blends the venues by how much has traded there, so the outcomes add up to 100%. Best Yes price is the cheapest ask across venues, and the payout is what a winning $100 stake returns before fees. Open a row for each venue’s contract name, bid and ask, and how closely their rules match.

Prices come from our regular polls of each venue, the oldest 1 min ago. Ages are as of when this page was built.

  • Polymarket
OpenAI
84.5%
Polymarket 86.5%(84.5% fair)polled, 1 min agoBest Yes 88¢ on Polymarket, $100 pays $114 (1.14x)
Polymarket
Contract
OpenAI
Last price
86.5%
Fair, margin removed
84.5%
As of
Polled 1 min ago
Buy Yes
88¢
Sell Yes
85¢
$100 on Yes pays
$114 (1.14x)
Volume
$12K
Trade this on Polymarket
Anthropic
5.3%
Polymarket 5.5%polled, 1 min agoBest Yes 8.1¢ on Polymarket, $100 pays $1,235 (12.3x)
Polymarket
Contract
Anthropic
Last price
5.5%
As of
Polled 1 min ago
Buy Yes
8.1¢
Sell Yes
2.8¢
$100 on Yes pays
$1,235 (12.3x)
Volume
$14K
Trade this on Polymarket
Meta
4.2%
Polymarket 4.3%polled, 1 min agoBest Yes 7.2¢ on Polymarket, $100 pays $1,389 (13.9x)
Polymarket
Contract
Meta
Last price
4.3%
As of
Polled 1 min ago
Buy Yes
7.2¢
Sell Yes
1.3¢
$100 on Yes pays
$1,389 (13.9x)
Volume
$2K
Trade this on Polymarket
Z.ai
1.5%
Polymarket 1.5%polled, 1 min agoBest Yes 2.7¢ on Polymarket, $100 pays $3,704 (37.0x)
Polymarket
Contract
Z.ai
Last price
1.5%
As of
Polled 1 min ago
Buy Yes
2.7¢
Sell Yes
0.3¢
$100 on Yes pays
$3,704 (37.0x)
Volume
$1K
Trade this on Polymarket
Google
1.1%
Polymarket 1.1%polled, 1 min agoBest Yes 2¢ on Polymarket, $100 pays $5,000 (50.0x)
Polymarket
Contract
Google
Last price
1.1%
As of
Polled 1 min ago
Buy Yes
2¢
Sell Yes
0.2¢
$100 on Yes pays
$5,000 (50.0x)
Volume
$2K
Trade this on Polymarket
Alibaba
0.9%
Polymarket 1%polled, 1 min agoBest Yes 1.6¢ on Polymarket, $100 pays $6,250 (62.5x)
Polymarket
Contract
Alibaba
Last price
1%
As of
Polled 1 min ago
Buy Yes
1.6¢
Sell Yes
0.3¢
$100 on Yes pays
$6,250 (62.5x)
Volume
$2K
Trade this on Polymarket
SpaceXAI
0.7%
Polymarket 0.7%polled, 1 min agoBest Yes 1.2¢ on Polymarket, $100 pays $8,333 (83.3x)
Polymarket
Contract
SpaceXAI
Last price
0.7%
As of
Polled 1 min ago
Buy Yes
1.2¢
Sell Yes
0.2¢
$100 on Yes pays
$8,333 (83.3x)
Volume
$1K
Trade this on Polymarket
Xiaomi
0.5%
Polymarket 0.5%polled, 1 min agoBest Yes 0.9¢ on Polymarket, $100 pays $11,111 (111x)
Polymarket
Contract
Xiaomi
Last price
0.5%
As of
Polled 1 min ago
Buy Yes
0.9¢
Sell Yes
0.1¢
$100 on Yes pays
$11,111 (111x)
Volume
$837
Trade this on Polymarket
Moonshot
0.4%
Polymarket 0.5%polled, 1 min agoBest Yes 0.7¢ on Polymarket, $100 pays $14,286 (143x)
Polymarket
Contract
Moonshot
Last price
0.5%
As of
Polled 1 min ago
Buy Yes
0.7¢
Sell Yes
0.2¢
$100 on Yes pays
$14,286 (143x)
Volume
$6K
Trade this on Polymarket
ByteDance
0.2%
Polymarket 0.3%polled, 1 min agoBest Yes 0.4¢ on Polymarket, $100 pays $25,000 (250x)
Polymarket
Contract
ByteDance
Last price
0.3%
As of
Polled 1 min ago
Buy Yes
0.4¢
Sell Yes
0.1¢
$100 on Yes pays
$25,000 (250x)
Volume
$1K
Trade this on Polymarket
Show 6 more outcomes
Poolside
0.2%
Polymarket 0.3%polled, 1 min agoBest Yes 0.4¢ on Polymarket, $100 pays $25,000 (250x)
Polymarket
Contract
Poolside
Last price
0.3%
As of
Polled 1 min ago
Buy Yes
0.4¢
Sell Yes
0.1¢
$100 on Yes pays
$25,000 (250x)
Volume
$2K
Trade this on Polymarket
DeepSeek
0.1%
Polymarket 0.2%polled, 1 min agoBest Yes 0.2¢ on Polymarket, $100 pays $50,000 (500x)
Polymarket
Contract
DeepSeek
Last price
0.2%
As of
Polled 1 min ago
Buy Yes
0.2¢
Sell Yes
0.1¢
$100 on Yes pays
$50,000 (500x)
Volume
$1K
Trade this on Polymarket
MiniMax
0.1%
Polymarket 0.1%polled, 1 min agoBest Yes 0.1¢ on Polymarket, $100 pays $100,000 (1000x)
Polymarket
Contract
MiniMax
Last price
0.1%
As of
Polled 1 min ago
Buy Yes
0.1¢
Sell Yes
—
$100 on Yes pays
$100,000 (1000x)
Volume
$659
Trade this on Polymarket
Mistral
0.1%
Polymarket 0.1%polled, 1 min agoBest Yes 0.1¢ on Polymarket, $100 pays $100,000 (1000x)
Polymarket
Contract
Mistral
Last price
0.1%
As of
Polled 1 min ago
Buy Yes
0.1¢
Sell Yes
—
$100 on Yes pays
$100,000 (1000x)
Volume
$799
Trade this on Polymarket
Tencent
0.1%
Polymarket 0.2%polled, 1 min agoBest Yes 0.2¢ on Polymarket, $100 pays $50,000 (500x)
Polymarket
Contract
Tencent
Last price
0.2%
As of
Polled 1 min ago
Buy Yes
0.2¢
Sell Yes
0.1¢
$100 on Yes pays
$50,000 (500x)
Volume
$1K
Trade this on Polymarket
Thinky
0.1%
Polymarket 0.1%polled, 1 min agoBest Yes 0.1¢ on Polymarket, $100 pays $100,000 (1000x)
Polymarket
Contract
Thinky
Last price
0.1%
As of
Polled 1 min ago
Buy Yes
0.1¢
Sell Yes
—
$100 on Yes pays
$100,000 (1000x)
Volume
$807
Trade this on Polymarket

Who resolves this market

Polymarket
Polymarket resolves via:
UMA optimistic oracle, source: arena.ai

How the odds have moved

The top 3 outcomes on both venues, with the consensus between them. Hover for exact values.

  • OpenAI
  • Anthropic
  • Meta

Order books

Each venue’s resting orders for the selected outcome’s Yes contract, side by side. Top of book streams live; depth refreshes every 15 seconds.

Polymarket

Open on Polymarket ↗

Top of book

Connecting
Best bid
—
Spread
—
Best ask
—

Waiting for the first live quote…

Depth · top 8 levels

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Recent trades

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What your stake buys

Enter a stake to see where it buys the most after fees, using each venue’s live order book.

$
Buy

Loading both order books…

Buys at the asks resting now (taker orders), cheapest after fees first, from order-book snapshots up to 15 seconds old. Fees: Kalshi 0.07 × price × (1 − price) per share, rounded up to the cent; Polymarket 0.05 × price × (1 − price) per share (other / general rate). Fee calculator. Estimates only, not advice.

About this market

Live prediction market odds for "Second-best Code Arena WebDev AI Lab end of October?". OpenAI leads at 84.5%. Next is Anthropic at 5.3%. $48K has traded across 16 outcomes on Polymarket. The market is expected to resolve by Oct 31, 2026.

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 October 31, 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. Note: Models marked “AutoEval” at the applicable check time will not be considered, regardless of whether they display a rank or score. 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".

Questions

What does the consensus price mean?

It is the price of a Yes contract that pays $1 if the outcome happens. A 14¢ price means traders put the chance near 14%. Where two venues list the same outcome, we blend their last prices, weighting the venue with more trading volume more heavily (neither counts for less than a quarter). When only one outcome can win, each venue’s prices add up to a little over 100% (its margin); the fair chance removes that margin so the outcomes add up to exactly 100%.

How is the payout worked out?

A Yes contract pays $1 if it wins, so at the best ask a $100 stake buys 100 ÷ ask contracts. At 18¢ that is about 555 contracts, paying $556 (5.56x) if Yes happens. Venue fees and price slippage on larger orders are not included.

Why do the venues show different prices?

Each venue has its own traders, fees and order book. Contracts can also settle on slightly different terms, which is why each row lists how closely the rules match.

Is a price gap an arbitrage?

Only when you can buy Yes on one venue below what someone pays for Yes on the other, after fees, and both contracts settle the same way. We show the executable bid and ask so you can check.

How fresh are these prices?

Venue prices refresh every few minutes, and the order book and live quotes stream continuously. Each venue’s card shows when we last observed it.

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