How the contract works
A contract on this question settles at $1 per contract if the CDC's Measles (Rubeola) counter shows 10,000 or more confirmed US cases for calendar year 2026, and at $0 if it does not; settlement is checked on 1 January 2027 using the CDC's own national tally, not state health department figures. The price at any moment is simply the market's collective estimate of that chance: a contract trading at 0.30, for example, would mean traders collectively see roughly a three-in-ten chance of reaching 10,000 cases, not that the outcome is guaranteed either way. Anyone holding a position can typically sell it before 1 January 2027 at whatever price the market is offering at that time, rather than waiting for settlement.
Yes7%
No93%
Probability
How the price has moved
The figure available for this market is a consensus of 7% concentrated on a single tracked venue, Polymarket, with roughly $6,525,064 in cumulative trading volume. There is no multi-venue spread to read here, since only one exchange is listed, and no day-by-day or week-by-week price history is available to describe how the figure has moved. What can be said plainly is that a 7% reading paired with several million dollars in volume reflects an actively traded, low-probability tail-risk contract rather than a market treating the outcome as either a foregone conclusion or a coin flip.
Analysis
Context
Measles was declared eliminated in the United States in 2000, meaning the virus no longer circulated continuously on its own; since then, outbreaks have been driven by imported cases seeding clusters in communities with low vaccination coverage. The worst year in the elimination era before the current one was 2019, when a Brooklyn and Rockland County outbreak tied to under-vaccinated communities pushed the national count to roughly 1,274 cases, the highest since 1992. In 2025, a large outbreak centered on an under-vaccinated Mennonite community in West Texas spread into New Mexico, Oklahoma and Kansas, producing the largest annual case count the country had seen in more than three decades. That outbreak, and the political fight over vaccine messaging and CDC leadership that followed it, is the backdrop against which the 2026 count is being watched. This market asks whether calendar year 2026 will produce a case count an order of magnitude larger than any year since elimination: 10,000 confirmed cases, as tallied by the CDC's national measles counter.
The consensus reading across tracked venues is 7%, all of it concentrated on a single venue, Polymarket, which has traded roughly $6,525,064 in volume on this question. A single-venue market with no competing price to check against means there is no spread to read for disagreement between platforms; the 7% figure is simply what buyers and sellers on that one exchange currently agree the chance is worth, backed by meaningful volume for a niche public-health contract. That volume suggests the question is being actively traded rather than sitting untouched, which matters because thinly traded contracts can show stale or unreliable prices; here, several million dollars of interest indicates the 7% figure reflects genuine disagreement being resolved through trading rather than a default guess. What the 7% level tells you structurally is that the market is pricing this as a low-probability tail event rather than a near-toss-up: consistent with the historical base rate, since even 2025's severe West Texas-driven outbreak did not approach a pace that would extrapolate to 10,000 cases for a full year. The decisive factor is not vaccination rates broadly, which move slowly, but whether any single 2026 cluster escapes containment the way 2025's West Texas outbreak did initially, and then keeps compounding across multiple states for months rather than being brought under control within a season. CDC's own reporting cadence and any disputes over how it counts or times cases add a layer of measurement uncertainty on top of the epidemiological question, since the settlement source is the CDC counter itself, not an independent tally.
What moves the probability
Vaccination coverage trend
National kindergarten MMR vaccination rates have been drifting below the roughly 95% threshold needed for herd immunity in a growing number of counties and states. Falling coverage in specific communities, rather than the national average, is what let 2025's West Texas outbreak take hold; further pockets of low coverage push the probability of a large 2026 outbreak upward.
Outbreak containment record
Every major US measles cluster since 2000, including 2019's New York outbreak and 2025's Texas outbreak, was eventually contained by state and local public health response within a matter of months. A strong containment track record is the main force keeping this probability in single digits, since a 10,000-case year needs containment to fail repeatedly, not just once.
CDC counter reliability and politics
The settlement source is the CDC's own national counter, which has faced public scrutiny over reporting lags and the political oversight of vaccine-related messaging at HHS. Any dispute over how or when cases are logged adds uncertainty to the measured outcome independent of the actual case count.
Historical base rate
No year since national elimination in 2000 has approached even a quarter of the 10,000-case threshold; 2019's 1,274 cases remains the modern high-water mark before 2025. This long run of years far below the threshold is the strongest downward pressure on the price.
New outbreak seeding events
A fresh, unrelated outbreak sparked by an imported case in a second under-vaccinated community, arriving on top of any existing 2026 clusters, would materially raise the odds of reaching a five-figure total. This is the scenario the market is implicitly pricing at roughly 7%.
The case for
- An existing or new 2026 outbreak would need to spread across multiple states without being contained through the fall and winter months, the way 2025's West Texas cluster nearly did.
- Vaccination coverage in one or more specific communities would need to remain low enough that local transmission chains continue rather than burn out, sustaining weekly case additions for most of the year.
- The CDC counter would need to keep recording and publishing cumulative case totals through 31 December 2026 without a data dispute large enough to shift the count materially.
- A pattern similar to 2025, but larger and less contained, would need to repeat in at least one region before mid-year to leave enough time to accumulate 10,000 cases.
The case against
- Every US measles outbreak since elimination in 2000, including the large 2025 cluster, has been brought under control by public health response well before reaching anything close to 10,000 cases nationally.
- The historical ceiling for a full year in the elimination era is roughly 1,274 cases in 2019, meaning 10,000 would require roughly an eightfold jump over the worst year on record.
- Local and state health departments have established outbreak-response protocols, including targeted vaccination campaigns, that have historically slowed spread within months of detection.
- No single reported cluster in 2026 has been described as being on a trajectory that would extrapolate to a five-figure annual total.
What to watch
The CDC publishes weekly updates to its national measles case counter, and consecutive weeks of accelerating case growth in any state would be the clearest early signal of a shift toward Yes. Watch for announcements of new outbreak clusters, particularly in communities with reported low MMR vaccination coverage, and for the start of the school year, which has historically been a period when under-vaccinated school populations drive transmission. The final resolution event is 1 January 2027, when the CDC's cumulative 2026 tally is read for settlement.
Trade this contract
Open on Polymarket
- gas covered
- no trading fee