Will a new pneumonic plague case be confirmed in Russia by October 15?
Crossbook compares what two exchanges, Polymarket and Kalshi, charge for the same event, and publishes a permanent scored record of its own forecasts under published rules.
Tracked on one venue, with Crossbook's own call on the record.
Bid/ask midpoint · retrieved 2026-10-15T17:20:27.461Z. Venue quote-update time is unavailable. Readings can be asynchronous.
0.6%bid 0.2% / ask 1.0%24h volume – · liquidity $5Kas of 15 Oct, 17:20 UTC · not refreshed recentlyView on PolymarketPrice, last 60 days
Crossbook forecast
- 10.8%against a market price of 14.5% at the timeNO
Logged 6 Oct 2026, 22:27 UTC · Brier 0.0116
- There is a live candidate event — a deceased Irkutsk laboratory worker with pneumonia of unknown etiology whose cause of death is not officially confirmed and for whom testing is reportedly underway — which lifts this above the near-zero base rate for a random 9-day window.
- However, initial testing found no microorganisms associated with her professional work, which is early disconfirming signal against Yersinia pestis, though not definitive.
- Pneumonic plague is highly transmissible person-to-person, and ECDC reports no secondary cases following the death — a meaningful signal against pneumonic involvement, since a genuine pneumonic case would be expected to seed contacts in some fraction of instances.
- Resolution requires an explicit announcement of a confirmed pneumonic case by 11:59 PM Moscow time on Oct 15; even if plague were ultimately implicated, Russian authorities may delay or never issue such an announcement within the 9-day window, and any unrelated new case arising in the window is at base-rate levels.
What would change it: An official announcement by Russian health authorities or WHO that laboratory testing confirmed Yersinia pestis with pneumonic involvement in the Irkutsk worker (or any other confirmed pneumonic case in Russia) before October 15.
Settlement sourcet-0228
Polymarket prices this at 0.6%. No verified equivalent is currently listed on the other venue, so there is no cross venue comparison on this page.
This market has settled. The page is kept as a record of what the market said while the question was open, and of what Crossbook called.
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