Will OpenAI or Anthropic IPO first?
Anthropic has the near-term procedural and commercial lead (earlier confidential S-1, stronger reported revenue run-rate), so I assess a high but not certain chance that Anthropic will IPO before OpenAI; my independent probability for the 'Yes' outcome is 78%.
Analysis
**Stage 1 — Blind analysis (ignore market price):**
Anthropic has a clear procedural edge: it confidentially filed its S-1 on June 1, 2026, a full week before OpenAI’s confidential filing on June 8. Confidential S-1s are not guarantees, but filing order is a meaningful operational signal because it reflects internal project timing, bank engagement, and readiness for SEC review. Commercial signals also favor Anthropic in the near term: multiple reports cite Anthropic’s faster revenue run-rate (~$47B annualized) relative to OpenAI (~$25B earlier in 2026), and Anthropic’s most recently reported private valuation (~$965B) is slightly higher than OpenAI’s (~$852B). Press narratives and insider reporting (Bloomberg and others) explicitly state that OpenAI insiders expect Anthropic to list first. Taken together, these concrete, recent facts make Anthropic the more likely first-to-market candidate in the near term.
Balancing factors against a firm prediction: both firms retain strategic flexibility. OpenAI’s leadership has publicly and privately signaled a willingness to delay to target a higher valuation (~$1T) and to manage listing timing to optimize price; that mindset creates a credible path for them to intentionally wait. Conversely, OpenAI could also accelerate — leveraging brand, investor demand, and underwriting resources — if market windows or competitive dynamics warrant. SEC review timelines, underwriter schedules, lockups, or last-minute corporate governance/regulatory issues could change either company’s timeline quickly. Confidential filings may also be withdrawn or re-filed if either company wants to alter the story.
Weighing the probabilities: given the filing order, the revenue and valuation posture, Bloomberg reporting on expected sequencing, and the lack of firm public launch dates for either firm, the fair independent probability that Anthropic will IPO before OpenAI is high but not certain. I assign **78%** to the Yes outcome (Anthropic first), reflecting a meaningful but not overwhelming edge — there is still a sizable 22% tail for OpenAI pulling ahead due to acceleration, strategic shifts, or unforeseen regulatory/filing issues.
**Stage 2 — Market calibration (look at market price):**
The current market price (Yes: 0.83) places implied probability at ~83%, slightly higher than my 78% independent estimate. That gap (about 5 percentage points) is modest. Possible reasons the market is a touch more bullish on Anthropic-first:
- Markets overweight filing order and press narratives as near-deterministic signals. Many traders treat a first confidential S-1 as a near-lock for being first to market, underestimating the possibility of strategic delays or re-filings. - Retail and momentum traders may have reacted to headline coverage and Bloomberg’s insider-sourced reporting, pushing the price up quickly and creating stickiness. - Liquidity concentration and directional bets by informed participants (e.g., funds that want a hedge on sector sequencing) can push the price beyond a pure fundamentals-derived probability.
Why the market might be slightly overpricing the Yes outcome: confidential filings are necessary but not sufficient for being first; SEC timelines, marketing decisions, or a tactical acceleration by OpenAI (given its resources and underwriter network) could still flip the order. Given those non-negligible possibilities, I view the market as slightly optimistic in favoring Anthropic first; the difference is small enough that the market still reflects the correct directional skew. Trading opportunities could exist for participants who want to take the contrarian exposure (selling Yes or buying No) if they put material weight on OpenAI’s ability to accelerate or on exogenous delays for Anthropic.
Arguments
For
- Anthropic filed its confidential S-1 earlier (June 1 vs June 8), giving it an operational lead in the IPO pipeline.
- Multiple reputable outlets (Bloomberg, NYT, CNBC) report that insiders expect Anthropic to list before OpenAI — independent corroboration across outlets increases credibility.
- Anthropic’s reported revenue run-rate and slightly higher private valuation (~$965B) provide commercial justification to proceed earlier.
- Banks and market participants expect the first AI mega-IPO to set pricing anchors, which can motivate the apparently-ready party (Anthropic) to push forward quickly.
- Anthropic’s public narrative and apparent readiness reduce the incentive for it to delay for marginal valuation gains, favoring an earlier debut.
Against
- OpenAI confidentially filed as well and retains the option to accelerate; its brand and investor demand could enable a faster push to market than observers expect.
- Both companies are strategically flexible — OpenAI’s leadership has signaled a preference for waiting to target a $1T valuation, which could mean they intentionally delay and make timing unpredictable.
- SEC review outcomes, underwriting logistics, or last-minute corporate governance fixes can change sequencing, and these are inherently noisy and opaque.
- Media/market narratives can be wrong; insider reports about expectations may reflect internal biases toward a story rather than deterministic timelines.
- A material macro shock or sector repricing could force both companies to pause, creating scenarios where neither debuts first in the near term and timelines converge.
Key drivers
- Relative confidential S-1 filing dates (Anthropic June 1 vs OpenAI June 8, 2026) and subsequent SEC review timing.
- Revenue momentum and commercial traction (reported run-rates: Anthropic ~ $47B vs OpenAI ~ $25B earlier in 2026).
- Strategic timing preferences from management — OpenAI’s stated willingness to wait for a higher valuation vs Anthropic’s apparent readiness to move sooner.
- Market conditions and investor appetite for large AI IPOs (banks’ willingness to price and underwrite a near-trillion-dollar offering).
- Regulatory or procedural shocks (SEC comment cycles, governance changes, or legal/regulatory scrutiny) that could delay either filer.
Risk factors
- Confidential S-1s can be revised, withdrawn, or delayed; first filing does not guarantee first listing.
- OpenAI’s greater brand power, investor pull, and deeper access to underwriting could allow it to accelerate faster than expected.
- Macro or sector volatility between filing and roadshow (equity market rout, banking stress) could halt one company while leaving the other unaffected.
- Regulatory scrutiny or governance issues could unevenly impact either firm’s timeline (e.g., SEC requests, national security concerns, or partner contract complications).
- Simultaneous or near-simultaneous listings (tie scenarios) could create ambiguity about which is 'first' if both price very close in time.
Scenarios
Best case
Anthropic proceeds smoothly: the confidential S-1 progresses through SEC review without major comments, market conditions remain receptive, and Anthropic launches a roadshow and prices an IPO in late 2026 — establishing a clear first-to-market status and validating the reported timeline.
Most likely
Anthropic maintains its procedural lead and lists before OpenAI (late 2026 to 2027 window), but the time gap is modest. OpenAI likely waits for a valuation/market window and lists afterward (2027 or later). There remains a non-trivial chance (~22%) that OpenAI accelerates or Anthropic delays, reversing the sequence.
Worst case
Anthropic faces an unexpected SEC comment cycle or commercial/regulatory issue that meaningfully delays its IPO while OpenAI accelerates (using superior underwriting and market influence) and lists first — flipping the expected order. Alternatively, both delay for multiple years or choose private alternatives (direct listings, SPACs, or remaining private), leaving the question unresolved for much longer.
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