Next Mythos-Class Model released by September 2, 2026?
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.
Crossbook forecast
- 13.0%against a market price of 54.5% at the timeYES
Logged 30 Aug 2026, 02:54 UTC · Brier 0.7569
- Cadence is the dominant signal: no frontier lab has shipped two same-tier flagship-class models ~85 days apart; June 9 to September 2 would be unprecedented compression of Anthropic's release cycle.
- Time decay is severe: with only 4 days left, even a genuinely planned early-September release misses the deadline unless it ships essentially immediately, and there is no cited announcement or event on the calendar.
- The main mitigant is that Anthropic historically releases models with little or no advance notice, so the absence of news is less informative than it would be for, say, Apple or Google events; this keeps the estimate in low double digits rather than near zero.
- The 54.5% market price sharply diverges from my estimate; plausible causes are thin liquidity ($2,148/24h volume), rumor-driven speculation about an imminent stealth drop, or information I don't have — low volume makes me discount but not dismiss the market's signal.
What would change it: A credible leak, API sighting, or official Anthropic announcement of a launch within the next 4 days would move this above 70%.
Settlement source
Context
Polymarket prices this at 99%. No verified equivalent is currently listed on the other venue, so there is no cross venue comparison on this page.
Volume over the last 24 hours is active, at about $50,629 on the busier venue.
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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Crossbook publishes every forecast it makes, timestamped before the answer is known and scored against the market afterwards. See the public record and the rules it is held to.