Scan: Will Anthropic have the highest IPO Market Cap 2026?

date	predicted	market price	confidence
2026-08-30	55%	60%	60%
2026-08-23	41%	45%	52%
2026-08-16	43%	39%	49%

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: polymarket_direct polymarket_related kalshi_related claude_news article_search gdelt_news wikipedia

Sub-questions (Fermi decomposition)

Has Anthropic filed confidentially or publicly for an IPO, hired banks, or signaled a 2026 listing timeline, and what is its latest private valuation?
Is SpaceX on track to IPO in 2026, at what expected valuation (reported ~$1T+), and has it filed an S-1 or set a date?
Which other mega-cap private companies (OpenAI, Stripe, Databricks, Shein, Revolut, Kraken, Cerebras, Klarna-like fintechs, Chinese/foreign giants) have announced or completed 2026 IPOs, and what are their first-day market caps so far?
What is the largest first-day closing market cap of any company that has already IPO'd in 2026 year-to-date?
What do Polymarket's sibling markets in this event imply for SpaceX, OpenAI, and other candidates, and do they sum consistently with Anthropic's price?
What is the historical base rate of AI labs / late-stage private companies converting stated IPO intentions into completed listings within the same calendar year?

Planner reasoning

This resolves on which company completing an IPO in 2026 has the largest first-day closing market cap; Anthropic wins only if it actually IPOs in 2026 and no larger listing (e.g., SpaceX, OpenAI, Stripe, Databricks, Shein, Revolut) occurs. Key drivers are Anthropic's own IPO timeline/valuation and the status of competing mega-IPOs, especially SpaceX which has been reported to target a 2026 listing at a far higher valuation. The Polymarket price is the primary anchor, with cross-market checks and news on IPO filings.

2. Research Parallel tool calls

tool	status	time	items	summary
polymarket_direct	OK	0.5s	1	## This Market's Polymarket Data Will Anthropic have the highest IPO Market Cap 2026? - Current price (probability): 57.05% - 7-day price change: -3.00% - 30-day price change: +47.05% - Total volume: $1,093,212 (USD notional) - Price range: 6.20% - 60.85% - Data points: 91 days
polymarket_related	OK	5.1s	0	Scanned 100 active Polymarket markets, kept 0 matches. keyword 'largest IPO 2026': 0 markets \| keyword 'Anthropic IPO': 0 markets \| keyword 'SpaceX IPO': 0 markets \| keyword 'OpenAI IPO': 0 markets \| keyword 'IPO market cap': 0 markets
kalshi_related	OK	4.9s	3	3 related markets / summaries. keyword 'Anthropic IPO': ok \| keyword 'SpaceX IPO': ok \| keyword 'largest IPO': ok
claude_news	OK	21.9s	9	Based on research findings: - SpaceX has already IPO'd (June 2026) and holds the largest IPO market cap of 2026 so far. SpaceX priced shares at $135, completing what stands as the largest initial public offering in financial history, raising approximately $75 billion at a valuation of $1.77 tr
article_search	OK	1.0s	40	Fetched 40 unique articles across 5 queries (lookback=60d). 'Anthropic IPO filing 2026': 10 articles \| 'SpaceX IPO 2026 valuation filing': 10 articles \| 'largest IPO 2026 market cap first day trading': 10 articles \| 'OpenAI IPO plans': 10 articles \| 'Stripe Databricks IPO 2026': 10 articles
gdelt_news	OK	65.7s	30	GDELT: 30 articles across 3 queries (lookback=30d). 'Anthropic IPO': 10 hits \| 'SpaceX IPO': 10 hits \| 'biggest IPO 2026': 10 hits
wikipedia	OK	0.1s	3	Fetched 3 Wikipedia entries (1 missing pages).

3. Evidence Brief Sonnet 5 · 6831 chars

# Current state Anthropic has NOT yet IPO'd: it confidentially filed an S-1 on 2026-06-01, is targeting a Nasdaq listing with marketing now expected to start mid-October 2026, and bullish reports peg a ~$2T valuation target. SpaceX has ALREADY IPO'd (2026-06-12) at a $1.77T offer valuation, popping 19.2% on day one to close near an implied ~$2.1T market cap — the figure Anthropic's first-day close must exceed to win this market. # Timeline of key events - 2026-05: Anthropic closes Series H at $965B post-money valuation, raising $65B (confirmed — CNBC/Wikipedia). - 2026-06-01: Anthropic confidentially files S-1 with SEC (confirmed — kucoin, CNBC). - 2026-06-12: SpaceX IPOs at $135/share (~$1.77T valuation); opens at $160.95, a 19.2% pop (confirmed — Yahoo Finance, CNBC). - 2026-06 (same period): OpenAI also confidentially files, but later reported shifting its IPO to 2027 (reported — kucoin, CNBC/NYT via CNBC 07-17). - 2026-07-15/16: Anthropic banks (Goldman Sachs, JPMorgan, Morgan Stanley) begin scheduling pre-IPO investor meetings (confirmed — CNBC). - Late 2026-08: SpaceX stock volatile — peaks near $2.2–2.6T within weeks of IPO, then pulls back ~30% from post-IPO high by 2026-08-29 (reported — Fool.com, SmartAsset). - 2026-08-13/17: Anthropic CFO Krishna Rao holds early "test-the-waters" investor meetings; no valuation discussed yet; Q2 revenue reported at $11.5B, annualized run-rate hits $65B by July (confirmed — CNBC). - 2026-08-21: Anthropic IPO filing expected to list "AI backlash" as key risk factor (reported — CNBC). - 2026-08-31: Shein lists in Hong Kong as part of broader China IPO boom (reported — Yahoo Finance). - 2026-09-05/06: Anthropic IPO marketing pushed from late-Sept to mid-October; prospectus disclosure delayed; $2T valuation target still cited by sources (reported — CNBC/Reuters via multiple outlets). # Event Will Anthropic achieve the highest first-day IPO closing market cap among all companies completing IPOs in 2026? # Outcomes to forecast Yes / No # Kalshi market anchor **No kalshi_direct price was returned for this ticker in the research.** Best available proxy: Polymarket direct market (same underlying event) shows **57.05% YES**, down 3pp over 7 days but up sharply (+47pp) over 30 days, with volume of ~$1.09M across 91 days. A related Kalshi market ("Will OpenAI or Anthropic IPO first? — Anthropic") trades at 94% YES, but that measures IPO order, not market cap size — not directly comparable. # Sub-question answers 1. **Anthropic IPO status/valuation** — Confidentially filed S-1 2026-06-01; $965B post-money valuation (May 2026 Series H); banks Goldman/JPMorgan/Morgan Stanley engaged; marketing timeline slipped from September to mid-October 2026; bull-case target ~$2T (Bloomberg/Fortune per claude_news). [CNBC, kucoin, Wikipedia] 2. **SpaceX 2026 IPO** — Already completed 2026-06-12 at $135/share (~$1.77T valuation); opened up 19.2% to $160.95, implying a first-day closing cap of roughly **$2.1T**; no S-1/filing pending since it's already public. [Yahoo Finance, CNBC] 3. **Other mega-cap 2026 IPOs** — OpenAI delayed to 2027 (removed as rival). SK Hynix cross-listed on Nasdaq (already publicly traded in Korea, raised $26.5B — unclear if counts under rules). Shein listed in Hong Kong (Aug 2026), no cap figures given. No confirmed 2026 IPOs found for Stripe, Databricks, Revolut, Kraken, Cerebras. [claude_news, gdelt_news] 4. **Largest first-day closing cap YTD** — SpaceX, at an implied ~$2.1T (June 12 close), is the largest 2026 IPO by a wide margin; described by multiple outlets as "the largest IPO in financial history." [Yahoo Finance, CNBC, Fool.com] 5. **Polymarket sibling markets** — polymarket_related found **zero** matching markets for "SpaceX IPO," "OpenAI IPO," or "largest IPO 2026" — no cross-market consistency check possible. 6. **Base rate of stated IPO intent → completion same year** — Not directly addressed in research (gap). Precedent within this dataset: OpenAI slipped its 2026 target to 2027, illustrating real execution/timing risk even for well-capitalized AI labs. # Key facts (high-confidence, factual) 1. [CNBC/Yahoo] SpaceX IPO'd 2026-06-12 at $1.77T valuation, closed day one up 19.2% (~$2.1T implied). 2. [CNBC/kucoin] Anthropic confidentially filed S-1 2026-06-01; $965B private valuation (May 2026). 3. [CNBC 09-05] Anthropic IPO marketing timeline pushed to mid-October 2026; ~$2T valuation floated. 4. [CNBC 07-17] OpenAI reportedly delaying IPO into 2027. 5. [Fool.com] SpaceX stock down ~30% from post-IPO high by 2026-08-29, but still trading near/above IPO price. # Cross-market signals - Kalshi related: Anthropic 94% to IPO before OpenAI (order, not size). - Polymarket direct (proxy for this exact event): 57% YES, volatile trend (sharp 30d rise, recent 7d dip). - Polymarket related: no sibling markets found for SpaceX/OpenAI/largest-IPO comparisons. - Sportsbook implied: none available. # Analyst opinions and speculation - Bloomberg/Fortune: Anthropic targeting ~$2T IPO valuation (speculative, unconfirmed pricing). - futuresearch.ai model: median 90-day post-IPO cap estimate ~$1.85T (below SpaceX's realized first-day cap). - Multiple outlets (WSOC/WSB/WPXI, same AP-style piece) frame Anthropic as possibly among "biggest IPOs ever" but stop short of claiming it will exceed SpaceX. # Directional lean per outcome - **Yes**: Strong revenue growth ($65B run-rate July 2026), OpenAI removed as a same-year rival, active bank-led process, bullish $2T target could produce a large first-day pop similar to SpaceX's 19%, potentially exceeding $2.1T. - **No**: SpaceX's first-day closing cap (~$2.1T) is already a high bar; Anthropic's disclosed/target valuations ($965B–$2T) sit at or below that mark even before accounting for IPO-day pop uncertainty; timeline has already slipped once (Sept→mid-Oct), raising execution risk; independent forecast model (futuresearch.ai) pegs Anthropic post-IPO cap below SpaceX's level. # Gaps / unknowns - No kalshi_direct YES price returned — using Polymarket (57%) as imperfect proxy. - Anthropic's actual IPO price/date/first-day close not yet determined (still pre-listing as of latest research). - SpaceX's precise official first-day closing market cap not directly confirmed (estimated via 19.2% pop math). - No data on base rate of AI-lab IPO-intent-to-completion conversion. - Unclear whether SK Hynix's Nasdaq cross-listing counts as a "2026 IPO" under resolution rules. # Calibration anchors - Polymarket proxy YES price: 57% (declining slightly last 7 days). - Kalshi related (Anthropic-before-OpenAI): 94% — different question, limited use. - Structural anchor: SpaceX's realized first-day close (~$2.1T) vs. Anthropic's disclosed valuation range ($965B–$2T) — Anthropic must exceed SpaceX's already-realized number, a nontrivial bar.

4. Forecasters Fable 5.1 + GPT-5.6 Sol · in parallel

claude-fable-5-1

42% conf

Yes	52%
No	48%

SpaceX has already set a very high bar with a ~$1.77T offer valuation and an implied ~$2.1T first-day close on 2026-06-12, and OpenAI's slip to 2027 removes the only other plausible rival. Anthropic's bull-case ~$2T target plus a SpaceX-like pop could clear that mark, and its $65B revenue run-rate supports rich pricing, but its marketing timeline has already slipped to mid-October (pricing likely November), leaving meaningful risk the IPO itself pushes into 2027, and the futuresearch model's ~$1.85T median sits below SpaceX's realized number. The Polymarket proxy at 57% YES (no Kalshi direct price) is the best anchor; I shade slightly below it to reflect the compounding of two hurdles — completing the listing in 2026 and exceeding ~$2.1T on day one — partially offset by resolution ambiguity that could favor offer-price comparisons (where $2T > $1.77T).

gpt-5.6-sol

62% conf

Yes	47%
No	53%

Anthropic’s confidential filing, bank-led preparations, and $65B revenue run-rate point toward completing a major 2026 IPO, while OpenAI’s delay removes the likeliest additional rival. However, SpaceX has already established an approximately $2.1T first-day closing market cap, above Anthropic’s speculative $2T target and well above its recent $965B private valuation. The mid-October marketing delay adds completion risk, and the independent $1.85T median estimate points toward No. I therefore move below the 57.05% Polymarket YES anchor, while retaining substantial Yes probability because even a modest first-day pop from a $2T offering could clear SpaceX’s mark.

5. Devil's Advocate Sonnet 5 · red-team critique

Both forecasters converge near 50/50 by lightly shading down from the 57% Polymarket proxy, but the brief's own "structural anchor" math (Anthropic's $965B–$2T range vs. SpaceX's already-realized ~$2.1T close) implies Anthropic needs both a top-of-range price AND a SpaceX-magnitude (19.2%) pop simultaneously — a compounding conjunction that arguably deserves a lower probability than either forecast assigns (~47-52%).

Neither forecast meaningfully engages with the explicit resolution-ambiguity gap flagged in the brief ("could favor offer-price comparisons where $2T > $1.77T") — F1 mentions it in passing without adjusting probability, F2 ignores it entirely, yet this ambiguity could swing the outcome by 10+ points depending on how "first-day closing cap" vs. "offer valuation" is judged.

Sub-question 6 (base rate of stated IPO intent → same-year completion) is explicitly flagged as an unaddressed gap, and the one concrete precedent in the brief — OpenAI slipping from 2026 to 2027 — is a same-category AI-lab example of exactly this risk; neither forecaster quantifies P(Anthropic completes its IPO by Dec 31, 2026) as a distinct multiplicative factor, they just fold "completion risk" qualitatively into the headline number.

Both treat Polymarket's 57% as a stable anchor, but the brief notes it's "up sharply (+47pp) over 30 days" then down 3pp recently on only ~$1.09M volume over 91 days — a thin, highly volatile market that may reflect noise/news-reaction rather than calibrated probability; neither forecast discounts for this instability.

Neither forecast considers dark-horse entrants (e.g., SK Hynix's $26.5B Nasdaq cross-listing, or an unlisted Stripe/Databricks surprise IPO) that could complicate the "highest cap" resolution even if Anthropic clears SpaceX, since the question is about being #1 among ALL 2026 IPOs, not just beating SpaceX specifically.

The futuresearch.ai model's ~$1.85T median (below SpaceX's ~$2.1T) is cited by both as a bearish input, but neither forecaster incorporates the variance around that median — a $1.85T median with typical IPO-pop dispersion could still yield a non-trivial chance of exceeding $2.1T on the tail, which should pull the estimate away from a clean coin-flip in either direction depending on how that distribution is modeled.

6. Aggregator Fable 5.1 · final calibrated forecast

46% (52% confidence)

Yes: 46% No: 54%

Anthropic must clear two compounding hurdles: actually complete its IPO in 2026 (marketing already slipped to mid-October, implying November pricing with little buffer, and the OpenAI precedent shows same-year slippage is real) and then post a first-day valuation above SpaceX's already-realized ~$2.1T close — which requires pricing near the top of the floated ~$2T range plus a meaningful pop, while the futuresearch median (~$1.85T) sits below the bar. Roughly 70-75% completion odds times ~55-60% odds of exceeding SpaceX conditional on listing yields ~40-45% on a strict first-day-close reading. I lift that modestly because resolution ambiguity (offer-valuation comparisons where $2T > $1.77T), OpenAI's exit as a rival, and Anthropic's $65B run-rate all favor Yes, and the Polymarket 57% proxy has presumably priced some of this in despite its thin, volatile trading. I land slightly below both forecasters and well below the market proxy at 46% Yes.

Pipeline Timing

Total pipeline time: 200.4s

Per-tool research timings shown in the Research section above.