SimpleFunctions
Winner-take-all answer·3 source contracts·Polymarket 3·refreshed just now·Closes May 31, 2026 · 2d

Measles cases in U.S. by May 31?

Bracket1925

Leader sits at 36% across 3 bound outcomes, runner-up at 4%. This is a winner-take-all market — the headline is the leader’s price, not an arithmetic mean.

Leader probability

36%

2000

runner-up 4¢leader 36¢

Outcomes

3

winner-take-all

Runner-up

2200

Spread

32pp

contested

24h volume

$13K

liquid

Closes

May 31, 2026

2 days

Venue

Polymarket

3 bound

30-day trend

0%50%100%-30d-3w-2w-1wtoday2000: 43% (11 days, 11 points)2000: 43% on 2026-05-282200: 4% (11 days, 10 points)2200: 4% on 2026-05-282400: 3% (11 days, 7 points)2400: 3% on 2026-05-28
200043¢22004¢24003¢
Top 3 candidates by current price · 11d

Bracket family

How the bracket ladder is priced.

Each row is one outcome on the venue. Sorted by 24h volume — the heaviest book is at the top.

Analysis

This market predicts whether U.S. measles cases will total 1,925 or fewer by May 31, 2026. The 96% probability reflects confidence that cases will remain below this threshold, with only 12 days remaining until resolution. Measles case counts depend on ongoing transmission rates, vaccination coverage, and outbreak containment efforts. The market assigns roughly equal probability (68–96%) to staying below 2,000 cases versus falling below 1,925, suggesting traders expect a relatively narrow final tally. Resolution occurs automatically on May 31 when CDC reports cumulative 2026 case data. Current momentum and the short timeframe suggest the outcome is largely determined by present transmission trends.

  • CDC reported measles surveillance data through mid-May 2026 will indicate whether year-to-date cases have accelerated or plateaued relative to contract thresholds
  • Vaccination rates and outbreak control measures in high-risk populations directly affect transmission velocity in the final 12 days
  • Any large institutional or healthcare outbreak detected and reported before May 31 could push cumulative cases across the 1,925 threshold
  • The 68¢ price on the 1,950-case contract implies traders see meaningful probability of the final count landing between 1,925 and 1,950
  • Low trading volume ($35–$232 per contract in 24 hours) suggests limited liquidity and potential for price movements on new case reports

What moved the line

  • May 27200023pp4825¢ · Polymarket
  • May 22200022pp1032¢ · Polymarket
  • May 28200018pp2543¢ · Polymarket
  • May 23200012pp3244¢ · Polymarket
  • May 25200010pp4454¢ · Polymarket

Recently closed in general

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.