Will OpenAI or Anthropic IPO first?
I assess that OpenAI is more likely than Anthropic to IPO first; my independent probability is 75% that OpenAI will list before Anthropic, driven by OpenAI's confidential S‑1 filing and explicit internal timing signal, though meaningful uncertainty remains.
Analysis
**Stage 1 — Blind analysis (ignore market price):**
OpenAI has taken two concrete steps that increase its probability of listing before Anthropic: a confidential S‑1 filing with the SEC and reported internal guidance from Sam Altman that an IPO could happen "within the next year" (while he simultaneously stressed timing remains flexible). Those items are strong, proximal signals in IPO sequencing: a confidential filing demonstrates management has already engaged the regulatory process and is preparing registration materials, and a CEO-level internal timeline typically correlates with near‑term execution unless market conditions intervene.
Anthropic is clearly on a similar pathway — reporting indicates it has also confidentially filed — but the public signals around timing are weaker: there is no widely reported Anthropic internal statement specifying a near‑term window comparable to Altman's "within the next year." That asymmetry in observable signals biases the sequencing toward OpenAI in the near term.
Other factual considerations temper certainty. Both firms are deep in capital markets conversations, both face the same macro windows (market appetite for large AI IPOs), both could accelerate or decelerate based on fundraising, revenue growth, or regulatory developments, and either could opt for alternatives (e.g., large strategic sale, continued private funding). OpenAI's unique corporate arrangements (Microsoft relationship, governance and investor structure) create both advantages (distribution, enterprise demand) and potential frictions (complex share structures, investor consent steps) that could either speed or delay a public listing.
Balancing these factors, I estimate a 75% independent probability that OpenAI will IPO before Anthropic. This reflects a strong but not overwhelming edge rooted in OpenAI's clearer near‑term signals and regulatory step, while leaving substantial room for Anthropic to beat OpenAI on timing via a faster internal decision, an aggressive filing cadence, or if OpenAI elects to delay.
**Stage 2 — Market calibration (now consider current market prices):**
The market currently prices Yes at ~80%. My independent 75% is close but meaningfully lower. Several reasons could explain why the market trades at 80%:
- Traders may overweight Altman's "within the next year" phrasing and the publicized confidential filing as near‑certainty rather than probabilistic signals, pushing price toward near unanimity. - Liquidity and momentum in this contract may be driven by retail and news‑reactive flows immediately after the filing story, which can overshoot true informational content. - Some market participants may have additional nonpublic or quickly forming information that increases confidence in OpenAI's lead (e.g., faster roadmap to roadshow, investment bank commitments), which would justify a higher price.
Conversely, the market may underprice Anthropic's chances. Reports that Anthropic also confidentially filed (albeit with less public timeline detail) mean Anthropic could still be competitive for the first slot; if Anthropic accelerated quietly, the market might lag in incorporating that possibility. Given the small gap between my probability and market price, I view the market as slightly optimistic about OpenAI but within a reasonable range; I do not see a glaring arbitrage unless one has stronger private information or a view on near‑term cadence of regulatory filing progress.
In sum: OpenAI is the frontrunner based on available public signals, and markets rightly price it as such; my independent assessment is 75% vs market 80%, reflecting modest skepticism about absolute near‑term certainty and acknowledging Anthropic's latent ability to preempt OpenAI.
Arguments
For
- OpenAI has a *formal confidential S‑1 filing*, which is the strongest public step toward an imminent IPO and typically precedes public listing cadence.
- A direct internal time marker from Sam Altman — "within the next year" — is a concrete near‑term planning signal that tends to correlate with earlier execution.
- OpenAI's deep commercial traction (large enterprise customers and Microsoft strategic partnership) increases its incentive to access public markets and institutional capital quickly.
- Public attention and media narratives around OpenAI increase pressure and momentum for a high‑profile listing, raising the probability it moves first.
Against
- Anthropic also reportedly confidentially filed; the absence of a public timeline does not preclude it from executing faster behind the scenes.
- Both companies may be strongly incentivized to time a market window; a short market downturn could prompt OpenAI to delay and allow Anthropic to move first.
- OpenAI's unconventional governance and complex investor agreements could introduce legal or structural delays that Anthropic may avoid.
- Either firm could accept a large private strategic transaction (e.g., deeper Microsoft stake or sale) that removes one from IPO sequencing entirely.
Key drivers
- Presence and timing of confidential S‑1 filings for each company (regulatory progress)
- Public/internal timing signals from leadership (Altman's "within the next year" vs Anthropic's unspecified timeline)
- Macroeconomic and IPO market windows (investor appetite for mega tech listings)
- Strategic relationships and revenue momentum (Microsoft ties, enterprise contracts, API revenue)
- Private capital alternatives (ability to raise more private funding or accept acquisition offers)
Risk factors
- Either company could voluntarily delay an IPO due to market volatility or valuation concerns
- Anthropic could accelerate its timeline or quietly complete gating steps faster than public reporting reveals
- Complex governance or investor consent issues at OpenAI could slow the listing process
- Regulatory interventions or political pressure on large AI firms could create new roadblocks or reporting requirements
- A major acquisition or strategic transaction (sale) could preclude one company from ever IPOing first
Scenarios
Best case
OpenAI completes the confidential S‑1 process, files publicly, completes a roadshow and prices an IPO within ~12 months, with Anthropic choosing to stay private longer or running a slower filing cadence — clear OpenAI first listing.
Most likely
Both firms proceed toward public markets within a similar multi‑year window, but OpenAI, supported by its confidential filing and Altman's near‑term internal guidance, most likely reaches the public markets first — though timing differences are narrow and contingent on market conditions and corporate decisions.
Worst case
Anthropic quietly accelerates its preparation and publicly lists before OpenAI, or OpenAI encounters governance/regulatory or market‑timing issues that delay its IPO for several years while Anthropic moves sooner; alternatively, one company is acquired, removing it from the race.
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