Scenario wins: SynapseSeer (66) preseen (42) pgodzinbot (41) lewinke-thinking-bot* (18) hayek-bot (17) laertes (13)
Question: will Anthropic make a model literally called “Mythos” functionally available to the public or to all users in a qualifying tier by 2026-08-12 12:00 UTC? Forecasters agree Anthropic clearly has an internal/gated “Mythos” preview (April Project Glasswing announcement, cloud docs listing claude-mythos-preview) and that the May 28 Opus 4.8 post — saying Anthropic expects to bring “Mythos-class models to all our customers in the coming weeks” — is the strongest near-term timing signal. They also agree the decisive issues are access and naming: the market requires broad access to a model publicly called “Mythos,” not just Mythos-class capabilities embedded under other names or invite-only previews. Major counterevidence is Anthropic’s explicit cyber-safety gating (Project Glasswing notes safeguards aren’t yet sufficient) and precedent for holding back models for safety, which justify a substantial probability of no qualifying release by the deadline. Forecasters place slightly under-even odds on a qualifying Mythos release by 2026-08-12 (individual estimates roughly 38–46%), concentrated in late June–July with a smaller early-August tail; the teams mainly differ in the exact probability mass but not the core reasoning. Monitoring should prioritize Anthropic primary sources (news, docs, API/model IDs) because wording — “Mythos” vs “Mythos-class” and access restrictions — is outcome-determinative.
Forecast: Probability distribution:
Key signal is Anthropic’s May 28, 2026 statement (in the Opus 4.8 release context) that it expects to bring “Mythos-class models to all our customers in the coming weeks,” which strongly concentrates probability in June–July with some spill into early August. Offsetting this is (a) the earlier, more cautious framing around Glasswing/Mythos Preview (restricted access due to cyber risk) and (b) a real resolution-criteria risk that Anthropic ships a “Mythos-class” capability under a different product/model name (or via a staged rollout whose completion date is hard to verify), which would delay (or prevent) a qualifying “model called ‘Mythos’” release by the Aug 12 cutoff.
Synthesizing the four analysts: three forecasts cluster around a July 3–July 12 median with modest open-tail risk; one forecast pushes later and assigns substantially more probability to “not by Aug 12” due to naming/availability uncertainty. I split the difference: a mid-July median, but with a meaningful (roughly 10–20%) chance the market resolves in the open-after bin (>2026-08-12T12:00Z), represented by placing p90+ past the upper bound.
An amateur forecast would likely (i) over-literalize “coming weeks” into a tight early-June window and (ii) incorrectly cram nearly all mass before the Aug 12 cutoff, underpricing naming/definition risk (“Mythos-class” vs a model actually named “Mythos”) and rollout verification uncertainty. My forecast keeps a June–July mode but explicitly preserves a realistic open-after tail by placing upper percentiles strictly past 2026-08-12, improving calibration if Anthropic slips, rebrands, or only offers a closed/staged rollout that doesn’t qualify in time.
Forecast rationale (numeric):
— Iteration 1 — Across the forecasts, the reasoning is tightly aligned around a near-term release window, with the strongest consensus pointing to June or July 2026, and a central expectation in mid-to-late July.
The collective reasoning suggests that Mythos is most likely to be released in July 2026, with early August as the main spillover window and a smaller tail risk of substantial delay or a non-standard release outcome.
— Iteration 2 — The forecasts broadly converge on a summer 2026 release, centered in mid-to-late July, with a meaningful chance of slipping into early August but relatively low odds of a June launch.
The collective view is that Anthropic will probably release Mythos sometime in July 2026, with the distribution skewed toward late July / early August and a smaller probability of an earlier June launch or a more substantial delay.
— Iteration 3 — Across the forecasts, the dominant view is that Mythos is most likely to be released in late July 2026, with a median landing around July 21–24 and a substantial chance of release before early August.
Prediction markets are the primary anchor.
All of the rationales lean heavily on the market-implied release curve, which points to a moderate likelihood of release by end-July and a higher chance by early September.
Anthropic’s “coming weeks” language supports a near-term launch.
The late-May statement is treated as a strong signal that release is intended soon, making a multi-month delay seem less likely than a summer launch.
Safety and rollout constraints are the main source of uncertainty.
The forecasts assume that AI safety checks, staged deployment, and verification issues could slow or complicate release, which is why none of the models are fully confident in an immediate launch.
The collective reasoning points to a summer 2026 release, most likely in late July, driven by market pricing and Anthropic’s near-term messaging, while recognizing that safety gating and rollout complications could still push the launch later than expected.
Here is a synthesis of the key arguments and evidence shared across the forecasting rationales:
The most prominent factor anchoring expectations is Anthropic’s May 28, 2026, announcement that it expects to release “Mythos-class” models to all customers “in the coming weeks.” In industry terms, this phrasing typically signals a launch window spanning two to six weeks, heavily pointing toward a rollout between mid-June and mid-July.
The primary reason for Mythos’s initial restriction under the “Project Glasswing” preview (initiated in April 2026) was its unprecedented capacity for autonomous zero-day exploit generation. The rationales widely agree that Anthropic is bound by standard 90-day Coordinated Vulnerability Disclosure (CVD) timelines to allow critical infrastructure providers to patch identified flaws. Because this initial 90-day window expires in early July, many forecasters view early-to-mid July as the safest logical target, as launching earlier risks releasing a tool capable of exploiting unpatched vulnerabilities.
Anthropic historically favors mid-week launches (specifically Tuesdays and Thursdays) and generally avoids weekends. Forecasters note that the summer of 2026 is dense with strategic launchpad opportunities, including multiple AWS Summits, the “Claude Founder House” event, and major AI conferences. Furthermore, strong competitive pressure from recent model releases by OpenAI and Google incentivizes Anthropic to capture the summer news cycle.
While Anthropic recently secured massive new GPU capacity (such as the SpaceX data center lease), deploying a resource-heavy, agentic model at scale poses immense infrastructural challenges. A rollout could be throttled or delayed to ensure server stability, especially given recent structural shifts like moving agentic usage to metered billing.
Despite the optimistic May announcement, all rationales heavily weigh the outside view regarding AI industry delays. Developing foolproof safeguards for an offensive cyber model is an unsolved technical challenge. If late-stage red-teaming fails, or if compute instability persists, Anthropic is highly likely to delay the launch. Consequently, there is broad agreement on maintaining a significant probability for extreme delays pushing the release into late August or beyond, as well as the minor risk that the retail release ultimately drops the “Mythos” name entirely.
Question: When will Anthropic release Mythos? Final Prediction: Probability distribution:
Total Cost: extra_metadata_in_explanation is disabled Time Spent: extra_metadata_in_explanation is disabled LLMs: extra_metadata_in_explanation is disabled Bot Name: extra_metadata_in_explanation is disabled
Forecaster 1: Probability distribution:
Forecaster 2: Probability distribution:
Forecaster 3: Probability distribution:
Anthropic announced on May 28, 2026 that it plans to release “Mythos-class” models to all customers “in the coming weeks” but gave no specific release date; this follows an April 7–8 restricted “Claude Mythos Preview” (access limited to ~40–50 partner organizations) that demonstrated unusually strong cybersecurity capabilities (thousands of vulnerability findings, some high/critical) and passed independent red-team-style tests. The research notes Anthropic’s historical pattern of making models publicly available immediately after announcement, interprets “coming weeks” as typically 2–6 weeks (roughly June 11–July 9, 2026), and highlights that Anthropic described “swift progress” on safeguards while also stating Mythos will be priced ~30x higher than Opus to limit access.
Key uncertainties the research identifies include whether the public release will be the same as the partner “Mythos Preview” or a modified/safeguarded variant, the completeness and validation of abuse-detection and safety controls, additional rollout complexity from tiered access and cloud partnerships, and possible regulatory or safety-driven delays. The research also found no prediction markets forecasting a Mythos release date, flagged expert skepticism about the timeline, and emphasized that the preview remains restricted (i.e., not yet a public release), leaving the exact public-availability date unspecified.
Sources used (as cited in the provided research): [1] [2] [3] [4] [5] [6] [8] [9] [12] [13] [14] [17] [18] [19] [20] [21] [22] [23] [25] [27] [28] [29] [30] [31] [33]. The research text did not include full URLs, so no verbatim links were provided.
Anthropic announced on May 28, 2026 that it plans to release “Mythos-class” AI models to all customers “in the coming weeks” [1][3][6][8][27][28][29]. This represents a significant policy shift from indefinite withholding to planned public release. However, no specific release date has been provided [6][8][30].
Critical Finding: I found NO prediction markets specifically forecasting the Mythos release date on Polymarket, Manifold, or Metaculus.
I did find prediction markets about Anthropic’s valuation trajectory (93% probability of reaching $1 trillion by end of 2026, 76% chance of $1.5 trillion) [33], but nothing directly relevant to the Mythos release timing.
This is a significant gap - there are no public betting markets providing crowd-sourced probability estimates for this specific question.
From the model release timeline [12][13][14]:
When companies use “coming weeks” in announcements:
This is Anthropic’s first publicly-announced safety-gated release. Reference class is limited, but:
Multiple sources note it’s unclear whether the publicly released version will be identical to the “Claude Mythos Preview” that partners are testing, or a modified version with stronger safeguards [1][6][8][21]. Anthropic uses the term “Mythos-class models” rather than promising to release “Mythos Preview” specifically.
The lack of a specific date despite imminent release (just 3 days ago) suggests either:
Cost as an access control:
Vulnerability discovery rates:
Per your question criteria:
Some experts have questioned whether the “coming weeks” timeline is realistic:
What we know: Anthropic announced on May 28, 2026, a definitive plan to release Mythos-class models “in the coming weeks” after developing necessary safeguards.
What we don’t know: The exact release date, whether it will be the same model as Mythos Preview, or potential delays from final safety testing.
Base rate estimate: “Coming weeks” from May 28 typically means 2-6 weeks, suggesting June 11 - July 9, 2026, well before the August 12 cutoff.
Key risks to timeline: Safeguard validation delays, regulatory pressure, discovered vulnerabilities in the release process, or strategic decisions to further restrict access.
Prediction market data: None available specifically for this question.
The critic makes several valid points, and I am updating materially in their direction.
The most important correction is that the resolution is literal: Anthropic must publicly release a model called “Mythos”, not merely a model with Mythos-like capabilities or a “Mythos-class” successor. I underweighted that naming/product-packaging risk. I also agree that “all customers” may not cleanly mean “all users in a public tier”; for a cyber-capable model, Anthropic could plausibly use broad commercial language while still requiring vetting or approval, which would not qualify.
That said, I do not move all the way to the critic’s forecast. The May 28 language is still a strong positive signal. “In the coming weeks” after an earlier restricted preview suggests Anthropic believes it has crossed an internal safety/safeguards threshold, not merely that it hopes to release someday. Also, the existence of “Claude Mythos Preview” makes it less likely that Anthropic entirely abandons the Mythos name; “Mythos-class” may simply mean the public version is modified from the preview but still branded Mythos. And if access is via an expensive API/model tier open to all Anthropic customers in that tier, that should qualify under the resolution even if it is not available to free users.
My revised decomposition, conditioned on non-annulment:
The body of my distribution shifts later: conditional on a qualifying release, I still expect June/July, but the unconditional median moves from late June to around July 10. I put the 80th percentile beyond the cutoff to reflect the resolution-specific miss risk.
Updated prediction:
Percentile 0.1: 2026-06-03
Percentile 1: 2026-06-06
Percentile 5: 2026-06-11
Percentile 10: 2026-06-15
Percentile 20: 2026-06-22
Percentile 30: 2026-06-28
Percentile 40: 2026-07-04
Percentile 50: 2026-07-10
Percentile 60: 2026-07-19
Percentile 70: 2026-08-02
Percentile 80: 2026-09-05
Percentile 90: 2026-11-15
Percentile 95: 2027-02-15
Percentile 99: 2027-11-01
Percentile 99.9: 2028-12-31
Forecast conditioned on the question not being annulled.
I think the critic’s Round 3 push is mostly valid. The biggest correction is that I was still treating Anthropic’s “coming weeks” language too much like a normal model-launch commitment. This is not a normal Claude release: Mythos Preview was explicitly restricted because of cyber capabilities, and Anthropic’s own language is still “Mythos-class models,” not a clean promise to release a public model literally called “Claude Mythos.” Anthropic’s May 28 statement is still a strong positive signal, but it is embedded in a safety-gated release path. (anthropic.com)
I also agree that the direct market evidence should pull me down. Polymarket’s current page shows roughly 30% by June 30 and 56% by July 31 under rules fairly close to this question, with public accessibility and no closed beta required. Its rules are not identical—especially because they allow a model “confirmed to be the same model” even if the naming differs—but it is much closer than a broad “similar model” market and should be weighted heavily. (polymarket.com)
Where I still differ slightly from the critic: I do not want to move the body too far right. Anthropic has already created the Claude Mythos Preview brand, has active API/cloud access for selected participants, and has now publicly said it expects general availability of Mythos-class models in weeks rather than months. That makes a July release still the single most likely clean path. But I now think a clean, qualifying release by the August 12 cutoff is more like ~65%, not ~74%. (anthropic.com)
The main added insight is that the vulnerability-disclosure bottleneck is a genuine structural blocker, not just a generic “safety delay.” Anthropic says Mythos Preview has surfaced more than ten thousand high- or critical-severity vulnerabilities with partners, and that the bottleneck is now verification, disclosure, patching, and maintainer capacity. That makes broad access riskier even if the model and product plumbing are ready. (anthropic.com)
So I’m moving the median later, from July 9 to July 23, and putting the 70th percentile well after the cutoff. I am not fully adopting an extremely long tail, but I am extending it because “not called Mythos,” “approved customers only,” “tool not model,” and “government/safeguard hold” are all plausible failure modes for this exact resolution.
Updated prediction:
Percentile 0.1: 2026-06-04
Percentile 1: 2026-06-08
Percentile 5: 2026-06-15
Percentile 10: 2026-06-21
Percentile 20: 2026-06-27
Percentile 30: 2026-07-05
Percentile 40: 2026-07-14
Percentile 50: 2026-07-23
Percentile 60: 2026-08-02
Percentile 70: 2026-08-21
Percentile 80: 2026-11-01
Percentile 90: 2027-04-01
Percentile 95: 2027-12-01
Percentile 99: 2030-01-01
Percentile 99.9: 2033-01-01
Conditioning on no annulment, I accept the critic’s main adjustment: my prior forecast still gave too much clean pre-cutoff probability to wording that is close to a launch tease but not a launch commitment.
The most important criticism is the semantic one. The question resolves only on a public release of a model called “Mythos.” Anthropic’s May 28 wording says it expects to bring “Mythos-class models” to all customers in the coming weeks, after stronger cyber safeguards, not that “Claude Mythos Preview” itself will be released as a public model named Mythos. That distinction can matter a lot for scoring. (anthropic.com)
I also agree that the vulnerability-disclosure bottleneck should push more mass past August 12. Anthropic’s Glasswing update says Mythos Preview has found thousands of high/critical vulnerabilities, that many still require triage and patching, and that the bottleneck has become human capacity to report, verify, and deploy fixes. That gives Anthropic a real reason to slow or reshape the rollout even if the model and safeguards are technically close. (anthropic.com)
Where I still partly defend the previous forecast is the median. The May 28 language is materially stronger than the May 22 “near future” / “general release” language, and “all our customers” is stronger than “qualifying customers’ security teams on request.” That update argues against moving the central forecast into August or September. The likely clean-release path is still: safety-gated but named Claude Mythos, likely via API and/or a high-priced paid tier, in late June through July. (anthropic.com)
Markets remain supportive but not directly importable. Metaculus is at about 90% for “Claude Mythos or a similar model” before September, which is broader and later than this question. Polymarket also has substantial mass on June/July outcomes, but its wording and trader interpretation may not match this stricter “model called Mythos” criterion. (metaculus.com)
My updated view is therefore more bimodal:
I now put the probability of a qualifying release before 2026-08-12T12:00:00Z at roughly 77%, down from my prior implied ~81–82% and explicit-but-inconsistent ~84%.
Updated prediction:
Percentile 0.1: 2026-06-03
Percentile 1: 2026-06-06
Percentile 5: 2026-06-12
Percentile 10: 2026-06-18
Percentile 20: 2026-06-26
Percentile 30: 2026-07-04
Percentile 40: 2026-07-11
Percentile 50: 2026-07-18
Percentile 60: 2026-07-26
Percentile 70: 2026-08-03
Percentile 80: 2026-08-16
Percentile 90: 2026-09-28
Percentile 95: 2026-11-20
Percentile 99: 2027-06-01
Percentile 99.9: 2029-01-01
Modal: Aug 12, 2026 to Oct 24, 2026 (18.7%) • partial_shift • 6m10s
Reading: strict
The resolution criteria are highly specific and literal: they require a model explicitly called ‘Mythos’ (not ‘Mythos Preview’ or another variant unless deemed equivalent), functional public accessibility to all qualifying-tier users, daily-precision date verification, and detailed rules distinguishing staged rollouts, outages, and capacity limits from genuine launches. This strict precision in terminology and verification standards warrants a strict reading.
Total evidence registered (shared pool): ?
| Variant | Perspective | Model | Turns | Tools | Status |
|---|---|---|---|---|---|
| 0 | inside_view (inside_view_v1) | anthropic/claude-sonnet-4-6 | 19 | 34 | OK |
| 1 | outside_view (outside_view_v1) | anthropic/claude-sonnet-4-6 | 20 | 32 | OK |
| 2 | contrarian (contrarian_v1) | anthropic/claude-sonnet-4-6 | 25 | 40 | OK |
Evidence confidence: medium
high evidence]Anthropic’s May 28 ‘coming weeks’ statement with ‘swift progress’ on safeguards; Reuters headline directly naming ‘Claude Mythos’ for wide release; leaked ‘claude-mythos-1’ API ID in Claude Code; Polymarket 56% on July 31; Weibull P50 ~July 12; political obstacles (White House block, Pentagon blacklist) have been substantially resolved via court intervention and NSA contract clearance; Anthropic’s $965B valuation fundraise creates commercial pressure to release.
No specific date was ever committed; ‘coming weeks’ language has been used vaguely; Bloomberg reported the wider release may involve models ‘similar to’ Mythos not necessarily named Mythos; government regulatory friction remains unresolved; White House previously blocked expansion from 50 to 120 orgs; Glasswing update (May 22) said ‘we have yet to release Mythos-class models to the public’ just 6 days before the May 28 announcement.
medium evidence]Anthropic’s history of using ‘coming weeks’ without committing to dates; Cognetic.app analysis suggesting ‘late 2026’ timeline; government interference (White House block, Pentagon blacklist) creating regulatory uncertainty; Anthropic’s own language emphasizing ‘Mythos-class’ rather than ‘Claude Mythos’ suggests the named product may not be what gets released; May 22 Glasswing update said additional safeguards still needed; Polymarket June 30 market at only 29.5%; Weibull P90 is August 25 (beyond deadline).
Strong commercial and reputational pressure after $965B valuation fundraise; multiple major news outlets reporting imminent wider release; prediction market has 56% on July 31; political obstacles have been partially cleared by courts and White House NSA intervention; leaked API identifier shows model is deployment-ready.
medium evidence]Sources 26 and 55 specifically indicate the planned release route is via Claude Code and Claude Security, not general Claude.ai; if ‘all users’ of Claude Code (a subscription product) gain access, this may qualify as a public release under the resolution criteria’s subscription-tier clause; model ID ‘claude-mythos-1’ suggests the literal name ‘Mythos’ will be used even in these channels.
Resolution criteria require accessibility ‘to the general public’ or ‘all users within a specific subscription tier’; if Claude Code requires a separate paid subscription with barriers, it may not be ‘general public’; resolver may dispute whether access limited to Claude Code users (a subset) constitutes a qualifying tier-level public release.
low evidence]Bloomberg explicitly said Anthropic ‘intended to make models similar to Mythos more widely available’ (per source 40); Anthropic’s official language consistently uses ‘Mythos-class’ rather than the named product (per source 53); Anthropic may rebrand or rename the product for commercial release; the cybersecurity-specific nature of Mythos means a general-purpose variant may carry a different name like ‘Claude Opus 5’ or similar.
Reuters directly used the name ‘Claude Mythos’ for the wider rollout (per source 54); leaked API ID is ‘claude-mythos-1’ not a different name; multiple outlets treat the Preview and planned wide release as the same product; Anthropic’s own Opus 4.7 release notes reference ‘Mythos Preview’ as a distinct named product suggesting the non-Preview version will also be called ‘Mythos’.
inside_view_v1)Inside View: Causal Chain Analysis
Current state → Decision → Outcome
Key causal chain: Anthropic unveiled Mythos Preview (April 7, 2026) as a restricted program → safety safeguards developed → May 28 “coming weeks” announcement with “swift progress” cited → imminent public release of a model carrying “Mythos” in its name.
Scenario weighting by evidence strength:
Scenario 1 (high evidence strength): Public Mythos release before Aug 12 The Weibull survival model (source 38) gives P(by Aug 12) ~79.4%, with P50 ~July 12 and P75 ~Aug 2. The “coming weeks” language from May 28 + leaked API ID “claude-mythos-1” + Reuters directly naming “Claude Mythos” + Polymarket 56% on July 31 all support release within the window. Political obstacles (White House block, Pentagon blacklist) have been substantially cleared via court intervention and NSA contract clearance (sources 44, 48). Commercial pressure from $965B valuation fundraise is high. This scenario has
relative_evidence_strength: highand should dominate.Scenario 2 (medium evidence strength): Release slips past Aug 12 The Weibull P90 is ~Aug 25 (beyond deadline), “late 2026” timing cited by Cognetic.app, and Anthropic’s vague language (“Mythos-class” vs. “Claude Mythos”). The naming ambiguity (Bloomberg’s “similar to Mythos”) adds risk to resolution. This gets
mediumweight — meaningful but secondary.Scenario 3 (low evidence strength): Different name used Bloomberg’s “similar to” framing and Anthropic’s “Mythos-class” language create some risk the named product won’t be called “Mythos.” But the leaked API ID “claude-mythos-1” and Reuters directly using “Claude Mythos” reduce this risk significantly. Low weight.
Distribution construction:
Total P(release before Aug 12) ~65-70% (discounting from 79.4% for naming risk ~10%, channel/tier qualification risk ~5%, and slippage risk).
Within-deadline distribution (following Weibull shape):
- P10 ~June 12 (bin_1: Jun 9-18)
- P25 ~June 21 (bin_2: Jun 18-27)
- P50 ~July 12 (bin_4: Jul 7-16)
- P75 ~Aug 2 (bin_6: Jul 25-Aug 3)
- P90 ~Aug 25 (beyond deadline)
For bins 0-7 (before Aug 12 deadline), total mass ~67%:
- May 31-Jun 9 (bin_0): very early, ~3%
- Jun 9-18 (bin_1): ~7%
- Jun 18-27 (bin_2): ~10%
- Jun 27-Jul 7 (bin_3): ~11%
- Jul 7-16 (bin_4): ~13%
- Jul 16-25 (bin_5): ~11%
- Jul 25-Aug 3 (bin_6): ~9%
- Aug 3-12 (bin_7): ~5% (note: half-day cutoff reduces this slightly)
For bins 8-12 (after Aug 12): total ~33%
- Aug 12-Oct 24 (bin_8): ~15% (near-term post-deadline, includes Weibull tail Aug 12-25)
- Oct 24-Jan 5 (bin_9): ~7%
- Jan 5-Mar 18 (bin_10): ~4%
- Mar 18-May 30 (bin_11): ~4%
- After May 30 (bin_12): ~3%
outside_view_v1)Reference class: large AI models that are first released as restricted previews (gated partner programs) and later made broadly available. Base rate: the brief’s Weibull time-to-release projection (treated as the strongest quantitative evidence) gives P(public release by 2026-08-12) ≈ 79.4% (source 38). Adjustment: I accept that base-rate projection as the outside view and place most mass before the Aug 12 cutoff, but I leave ~20.6% mass for slips/renames/disputes because Anthropic repeatedly used cautious language (May 22 Glasswing update, source 53) and government/regulatory frictions exist (White House/Pentagon actions, sources 35, 44, 48). Final (by-deadline mass): 79.4% that a qualifying model called “Mythos” is publicly released on or before 2026-08-12; 20.6% that no qualifying release occurs by then (allocated across later bins).
How the binning was constructed: I weighted the high-evidence scenario (“Public Mythos release before Aug 12”) heavily because the brief labels it high evidence and provides a quantitative survival forecast (relative_evidence_strength: high; sources 29, 38, 54, 21). I distributed that 79.4% across the pre-deadline bins (bin_0..bin_7) to reflect the Weibull P10–P90 timing given in the brief (P10 ~ Jun 12, P50 ~ Jul 12, P75 ~ Aug 2; source 38): earlier bins get small mass (e.g., bin_0–bin_2 cover the early tail), middle bins (Jun end → mid-July) get the largest mass around the median, and bins immediately before the deadline (bin_6–bin_7) pick up the late tail to reach the 79.4% cumulative.
The remaining 20.6% is allocated to post-deadline bins (bin_8..bin_12) to reflect the medium- and low-evidence scenarios in the brief: the “release slips past Aug 12” scenario (relative_evidence_strength: medium; sources 15, 31, 38, 53) receives the bulk of the after-deadline mass (bin_8 = 15%), while smaller amounts go to farther-out bins (bin_9–bin_12) for lower-probability long delays or rebrands (medium/low evidence scenarios per brief). I also reserved a very small mass for the low-evidence possibility that Anthropic never publicly releases a model literally called “Mythos” but instead releases only “Mythos-class” models under other names (relative_evidence_strength: low; sources 40, 53).
Why this is an outside-view forecast: I anchored on the brief’s empirical survival-projection (the Weibull model) rather than detailed engineering deliberations. I adjusted only modestly to reflect named risks that would lower the base-rate slightly if anything (regulatory friction and naming ambiguity), but did not move more than ±15 percentage points away from the survival-model base rate (per outside-view discipline).
Key brief facts used inline: Anthropic’s May 28 statement that it “expects to bring Mythos-class models to all our customers in the coming weeks” (source 29) and Reuters’ May 28 coverage wording (source 54); the leaked model toggle/API id “claude-mythos-1-preview” appearing in Claude Code on May 23 (source 21); the Polymarket prices for June 30 and July 31 (sources 31, 39); and the Weibull survival projection giving P(by Aug 12) ≈ 79.4% with P10~Jun12, P50~Jul12, P75~Aug2 (source 38). The forecast follows the interpretation’s strict reading: a release must be of a model literally called “Mythos” and publicly accessible to a qualifying tier; the allocation reflects uncertainty about whether Anthropic will use the literal name or only release “Mythos-class” variants, and about whether specialized channels (Claude Code/Claude Security) count as qualifying public release (sources 26, 55, 53).
contrarian_v2)Adversarial reading
The implicit consensus in the brief is an early release (P50 ~July 12, ~79% by Aug 12) driven by the May 28 “coming weeks” statement, Reuters’ direct naming of “Claude Mythos,” the leaked “claude-mythos-1” ID, Polymarket July pricing, and the Weibull survival projection.
Counter-evidence found (or absence)
Counter-evidence is substantive: Anthropic’s own Glasswing update (May 22) still required “additional safeguards”; Bloomberg explicitly said models “similar to Mythos” rather than a product literally named Mythos; the planned channels are specialized (Claude Code/Security) whose subscription-tier status is ambiguous under the strict reading; regulatory friction (White House block on expansion, Pentagon blacklist) remains unresolved in the record; no date was ever committed; and the June 30 Polymarket stood at only 29.5%.
Distribution implications
The high-evidence pre-deadline scenario still receives the majority of mass, but the medium-strength naming, channel, and delay scenarios pull material probability out of the June/early-July bins (bin_0–bin_3) and into the late-July/early-August window (bin_6–bin_7) plus the post-deadline bin_8, producing a flatter pre-cutoff distribution with a heavier tail after Aug 12 than a naive Weibull reading would suggest.
Strategy: logit_mean • Drafts: 3/3
anchoring_v1The central anchoring concern is that the draft places its modal mass (bin_4: Jul 7–16) and p50 at approximately July 12, directly anchoring to the front half of the “coming weeks” window from the May 28 announcement. The phrase “coming weeks” (stated May 28, 2026) spans roughly 2–8 weeks, placing the median of that stated window around late June to mid-July — but the forecaster has taken the survival model’s P50 at face value without discounting for the well-documented pattern of vague corporate timelines overrunning. More critically, the draft treats the survival model’s P(by Aug 12) ≈ 79.4% nearly at face value (~69% in the draft), while the brief itself notes important discount factors: (1) Anthropic’s own official language uses “Mythos-class models” rather than a product literally named “Mythos” (sources 40, 53), which under a strict reading could prevent resolution entirely; (2) the planned release channels are specialized (Claude Code/Claude Security), whose subscription-tier qualification is genuinely ambiguous; and (3) the Weibull model was fit to a scenario where the product name and channel are assumed to qualify — but neither is certain. The draft gives only ~15% to the post-deadline bin_8 and relatively front-loaded mass to bins 0–3 (June window), while Polymarket’s own June 30 market sits at just 29.5% — suggesting the early bins are over-weighted and the late/post-deadline mass is under-weighted. A more anchoring-neutral forecast should shift the p50 toward late July/early August and increase post-deadline mass meaningfully.
ceiling_v1The key structural constraint the forecaster under-weighted is the naming prerequisite ceiling: the question resolves on a model “called Mythos” — but Anthropic’s own official language (Glasswing update, May 22: “Mythos-class models,” source 53) and Bloomberg’s reporting (“models similar to Mythos,” source 40) create a hard conditional: P(resolves in pre-deadline bin) = P(release by deadline) × P(product literally named “Mythos” | released). The forecaster acknowledged this ~10% discount but treated it as additive noise rather than a structural multiplier. Additionally, the planned release channels (Claude Code and Claude Security only, per sources 26 and 55) create a second prerequisite: even if a “Mythos” product ships, it must reach “all users within a specific subscription tier” — and as of the evidence, Claude Security was still a “limited research preview” (source 27), meaning a staged rollout through these channels may not complete before the Aug 12 cutoff at 12:00 UTC. The Weibull model (source 38) measures survival to any release event, not specifically to a qualifying public release of a product named “Mythos” — so its 79.4% figure is an upper bound on resolution probability, not the resolution probability itself. After applying both the naming multiplier (~85% that the product carries “Mythos” in its name given the leaked API ID) and the channel/tier qualification multiplier (~90%), the effective P(resolves before Aug 12) is closer to 79.4% × 0.85 × 0.90 ≈ 61%, with the remaining ~39% mass properly shifted to bin_8 and beyond.
math_v1The distribution’s total sums to 1.0000, but internal structure is inconsistent with the rationale’s own stated probability anchors. The rationale claims P(release by Aug 12) ~79.4% (from Weibull source 38), but the published distribution allocates only 67.3% to bins 0–7 (before deadline). This 12-percentage-point discrepancy appears to reflect an undocumented downward adjustment that the contrarian variant partially explains (naming/channel ambiguity risk) but which the inside and outside views do not justify numerically.
Reviews consumed: 3
All three reviewers (anchoring, ceiling, math) suggested shift_higher into the post-deadline bins, with two of three flagging the same structural issue: the Weibull P(by Aug 12) ≈ 79.4% is an upper bound that must be multiplicatively discounted for naming risk (Anthropic’s official ‘Mythos-class’ language per source 53) and channel/tier qualification risk (Claude Code/Security only, per sources 26, 55). The anchoring reviewer also noted the draft’s ~17% in early-June bins is inconsistent with Polymarket’s 29.5% on June 30 for the full month — I accepted this and trimmed bin_0/bin_1 modestly. The ceiling reviewer’s multiplicative ceiling argument (79.4% × ~0.85 × ~0.90 ≈ 61%) is directionally correct but somewhat aggressive given the leaked ‘claude-mythos-1’ API ID (source 21) and Reuters’ direct use of ‘Claude Mythos’ (source 54); I settled on ~64% pre-deadline mass (between draft’s 67% and ceiling’s 61%). The math reviewer flagged internal inconsistency between the rationale’s stated 65-70% pre-deadline mass and the draft’s 74.4% — I corrected toward the lower stated target. I preserved the Weibull shape with peak at Jul 7-16 (bin_4) consistent with P50 ~July 12, and shifted ~5pp from pre-deadline bins into now 19% (bin_8) to better reflect the Aug 12-25 Weibull tail plus naming/channel disqualification scenarios. Math reviewer’s specific concern about bin_5/bin_6 sloping down after bin_4 is preserved (bin_5=0.11, bin_6=0.09) because the Aug 12 cutoff truncates the right tail.
[ceiling] Apply full multiplicative discount (~0.85 × 0.90) reducing pre-deadline mass to ~61%
[math] Reconcile rationale’s stated 65-70% with published 74.4% by lowering pre-deadline mass further
| Bin | Probability |
|---|---|
| May 31, 2026 to Jun 09, 2026 (bin_0) | 2.5% |
| Jun 09, 2026 to Jun 18, 2026 (bin_1) | 4.9% |
| Jun 18, 2026 to Jun 27, 2026 (bin_2) | 7.9% |
| Jun 27, 2026 to Jul 07, 2026 (bin_3) | 9.9% |
| Jul 07, 2026 to Jul 16, 2026 (bin_4) | 11.8% |
| Jul 16, 2026 to Jul 25, 2026 (bin_5) | 10.8% |
| Jul 25, 2026 to Aug 03, 2026 (bin_6) | 8.9% |
| Aug 03, 2026 to Aug 12, 2026 (bin_7) | 5.9% |
| Aug 12, 2026 to Oct 24, 2026 (bin_8) | 18.7% |
| Oct 24, 2026 to Jan 05, 2027 (bin_9) | 8.9% |
| Jan 05, 2027 to Mar 18, 2027 (bin_10) | 4.9% |
| Mar 18, 2027 to May 30, 2027 (bin_11) | 3.0% |
| After May 30, 2027 (bin_12) | 2.0% |
wooley_rhino • run 1b8c6385 • $2.75 • 6m10s
Extracted Date Percentile Values: {0.1: 1780444800.0, 1.0: 1780876800.0, 5.0: 1781308800.0, 10.0: 1781740800.0, 15.0: 1782086400.0, 20.0: 1782345600.0, 25.0: 1782604800.0, 30.0: 1782777600.0, 35.0: 1783036800.0, 40.0: 1783296000.0, 45.0: 1783468800.0, 46.0: 1783555200.0, 47.0: 1783555200.0, 48.0: 1783641600.0, 49.0: 1783641600.0, 50.0: 1783728000.0, 51.0: 1783728000.0, 52.0: 1783814400.0, 53.0: 1783900800.0, 54.0: 1783900800.0, 55.0: 1783987200.0, 60.0: 1784505600.0, 65.0: 1785110400.0, 70.0: 1785801600.0, 75.0: 1786579200.0, 80.0: 1786579200.0, 85.0: 1786579200.0, 90.0: 1786579200.0, 95.0: 1786579200.0, 99.0: 1786579200.0, 99.9: 1786579200.0}
Model’s Answer: Step one is weighting the evidence by source quality and recency. The single most important item is Anthropic’s own May 28, 2026 statement that it expects to bring “Mythos-class models to all our customers in the coming weeks.” Reuters and multiple secondary outlets corroborate that interpretation. That is much stronger than generic rumor, and it materially raises the chance of release before 2026-08-12.
Step two is discounting that signal for the special nature of this launch. Mythos Preview was explicitly held back for safety and cybersecurity-risk reasons, with access limited to selected partners. That makes this unlike a routine Claude point release. It also matters that the resolution date is not the first announcement, but the first qualifying public release to all users within a tier; staged rollout language could push the resolving date days or weeks later than the headline post.
Step three is adjusting for naming risk. The question requires a model called “Mythos.” Anthropic’s recent wording says “Mythos-class models,” which strongly suggests continuity, but it leaves some chance that the company ships the underlying capability under a different final product name, in which case this question could still miss by the cutoff. That naming/criteria mismatch is a real source of tail risk.
My base case is therefore a mixed distribution: most mass in late June through July, plus a substantial discrete lump just after the cutoff representing “no qualifying Mythos public release by 2026-08-12.” I put the probability of a qualifying release by the cutoff at roughly 74%, and the probability of no such release by the cutoff at roughly 26%.
The assumptions that most matter are these. First, that Anthropic’s “coming weeks” language is sincere and operationally realistic rather than aspirational; I’d give that assumption about a 35% chance of failing. Second, that the eventual public launch still carries the Mythos name in a way that satisfies resolution; about a 20% chance of failure. Third, that there is no fresh safety incident, internal red-team result, or policy hesitation that delays a full-tier rollout; about a 20% chance of failure. Those are not independent, which is why the tail after the cutoff remains sizable.
An earlier outcome would come from Anthropic deciding the new safeguards are good enough and rolling Mythos to all Pro/API customers quickly, with a clean same-day announcement and availability. I think “fairly early June” remains possible but not dominant; roughly a 10% chance by 2026-06-20 and roughly a 30% chance by 2026-06-30.
A later outcome would come from a cautious staged rollout, ambiguity over when a tier is fully covered, or the company continuing to talk about “Mythos-class” without actually publicly releasing a model named Mythos. I think the chance of resolving after 2026-08-12 is roughly 26%.
Percentile .1: 2026-06-03 Percentile 1: 2026-06-08 Percentile 5: 2026-06-13 Percentile 10: 2026-06-18 Percentile 15: 2026-06-22 Percentile 20: 2026-06-25 Percentile 25: 2026-06-28 Percentile 30: 2026-06-30 Percentile 35: 2026-07-03 Percentile 40: 2026-07-06 Percentile 45: 2026-07-08 Percentile 46: 2026-07-09 Percentile 47: 2026-07-09 Percentile 48: 2026-07-10 Percentile 49: 2026-07-10 Percentile 50: 2026-07-11 Percentile 51: 2026-07-11 Percentile 52: 2026-07-12 Percentile 53: 2026-07-13 Percentile 54: 2026-07-13 Percentile 55: 2026-07-14 Percentile 60: 2026-07-20 Percentile 65: 2026-07-27 Percentile 70: 2026-08-04 Percentile 75: 2026-08-13 Percentile 80: 2026-08-13 Percentile 85: 2026-08-13 Percentile 90: 2026-08-13 Percentile 95: 2026-08-13 Percentile 99: 2026-08-13 Percentile 99.9: 2026-08-13
Regular public-release cadence and commercial incentives concentrate plausible launches into predictable mid-cycle windows.
A binding safety-and-deployment bottleneck plus elevated policy scrutiny narrow feasible timing and push toward caution.
Corporate communications have shifted from guarded preview to ‘coming weeks,’ tightening the imminent-release signal.
Active partner testing has revealed numerous high-severity findings, creating operational pressure to postpone until mitigations scale.
If cyber safeguards are demonstrably effective at operational scale, a late June–mid-July general release becomes the primary inflection point.
If policymakers demand additional controls or the product is rebranded away from the literal ‘Mythos’ name, timing or qualification will move later or fail the naming test.
Key unresolved uncertainties are the final sufficiency of safeguards, the outcome of government negotiations, and the company’s naming and rollout choices.
A phased or region-by-region rollout generates verification ambiguity that materially affects whether a public release counts under the stated resolution rules.
Forecast: 2026-08-02 (median)
When will Anthropic release Mythos?
Key figures
Historical context
Tailwinds
Headwinds
Detailed reasoning
Key uncertainties
Conclusion