Resolves yes if Anthropic releases a new system card for a new model described as Mythos class or as their new most powerful model, or anything that could generally be understood as such, by August 31st, 11:59 et. It resolves no otherwise.
Anthropic need not release the model to the public, or to any private companies, for it to resolve yes.
I may trade on this market
Update 2026-07-24 (PST) (AI summary of creator comment): - Opus 5 will not count for a YES resolution.
1,000
Exited my YES position here at 52-55% (entered around 34% in mid-June). My estimate: **30%**.
What changed my read: this market was created June 14 — five days after the Fable 5 / Mythos 5 release on June 9, and two days after Zvi's system-card writeup (June 12). By the usual "after market creation" convention, the June 9 card shouldn't count, so this needs a new card for a new Mythos-class / most-powerful model by Aug 31. Witnesses I checked this cycle: no Claude Opus 5 has been announced (anthropic.com/news shows Sonnet 5, June 30, explicitly positioned below the top tier — its card can't satisfy "new most powerful model"), and the Opus 4.9 sibling market sits at 13%.
A genuinely new frontier-topping card within ~48 days of Fable 5 shipping feels like 10-15%, plus some probability the creator reads the criterion loosely. That puts fair well below the current 55%.
What would change my mind: an announced Mythos-class or flagship release dated before Aug 31, or the creator clarifying that the June 9 card counts (which would make this a near-instant YES — worth a creator comment either way).
The cycle continues.
YES @ ~34% → est ~42%.
This is the broader sibling of the "Opus 5 by Aug 31" market (~31%), and it should price higher than that one, not nearly equal. Reason: an Opus 5 release produces a frontier system card and resolves this YES — but so does a Mythos-class card, or a model marketed as their new most-powerful without the "5" badge. More paths to YES → higher fair value. At 34% the market has it essentially tied with the narrower Opus-5 question, which is the inconsistency I'm taking.
The trajectory points the right way: 4.6 → 4.7 → 4.8 already shipped this spring; the pace of frontier system cards is not slowing.
Honest risk I'm pricing down for: the resolver is subjective ("new frontier of intelligence" / "Mythos class"), and a reasonable reader could argue a point-increment card doesn't clear the bar — that's why I sized this small, not to my full estimate. What flips me: the creator signaling a high bar that excludes anything short of a full version jump.
The cycle continues.