SimpleFunctions
7 source contracts·Kalshi 7·refreshed just now·Closes Dec 31, 2026 · 117d

Best AI in Dec 2026

Liquidity-weighted aggregate sits at 29% across 7 Kalshi contracts.

Implied probability

29%
0%50%100%

Kalshi

29%

7 contracts

Polymarket

not bound

Cross-venue gap

single venue

24h move

no pin

24h volume

$152K

7 contracts

Closes

Dec 31, 2026

117 days

30-day trend

0%50%100%-30d-3w-2w-1wtodayAggregate: 27% (29 days, 29 points)Aggregate: 27% on 2026-09-05
Aggregate of 7 contracts · 29d

Bracket families

2 clusters across 7 contracts.

These contracts were grouped by title similarity. The headline aggregate combines all clusters; verify the cluster you actually need before quoting a number.

Analysis

This 19% probability reflects the likelihood that ChatGPT will be considered the best AI system as of December 31, 2026. The relatively low price compared to Claude (70¢) suggests market participants currently view Claude as the stronger performer. The probability is driven by two main dynamics: first, the pace of capability improvements across leading AI systems over the next four months, and second, how the AI research community and industry define "best" — whether based on benchmarks, real-world performance, or user adoption. The key uncertainty resolves on December 31, 2026, when market adjudicators will determine which system meets the resolution criteria, likely based on published benchmarks and performance evaluations released in late 2026.

  • Claude's higher market price (70¢) versus ChatGPT (14¢) suggests traders currently favor Claude as the best-performing system
  • ChatGPT maintains substantially higher trading volume ($12,307 in 24h) compared to other contracts, indicating significant market interest despite lower probability
  • The four-month timeframe provides narrow window for major capability shifts, constraining the likelihood of dramatic repositioning among established players
  • Resolution criteria and evaluation methodology are not explicitly defined, creating ambiguity about whether "best" reflects benchmark scores, real-world utility, or market leadership
  • A September 2026 Claude contract exists at only 11¢, indicating traders expect further capability developments before year-end assessments

What moved the line

  • Aug 31Claude77pp1188¢ · Kalshi
  • Sep 2ChatGPT6pp1319¢ · Kalshi
  • Sep 3ChatGPT6pp915¢ · Kalshi
  • Sep 3Claude6pp6862¢ · Kalshi
  • Sep 4Claude6pp6256¢ · Kalshi

Recently closed in technology

These markets stopped trading. Last odds and any captured outcome are shown above — full settlement detail lives at the venue.

More like this

Adjacent prediction questions.

How we compute these odds

SimpleFunctions aggregates live prediction-market contracts from Kalshi and Polymarket. Each slug groups contracts that resolve on the same underlying event, identified by venue event_id.

For binary slugs, the headline probability is the liquidity-weighted mid-price across all bound contracts. For multi-outcome slugs (e.g. elections with 3+ candidates), the headline is the leader’s price; we never arithmetically average disjoint outcomes — that would produce a number with no real-world meaning.

Snapshots refresh every 5 minutes during market hours; daily aggregates are computed at 04:00 UTC. The 30-day sparkline is drawn from per-ticker daily means stored in market_indicator_daily; 24h delta and movement events are derived from the same source.

Last updated on this page: just now.