Will OpenAI or Anthropic IPO first?

**Stage 1 — Blind analysis (ignore current market prices):**

Anthropic currently has stronger near-term indicators of being first to market. The company confidentially filed an S-1 on June 1, 2026, is publicly targeting an October 2026 Nasdaq listing, and just completed financing that supports a near-$1T private valuation. These are concrete, forward-facing signals: a target month, a completed large funding round, and active engagement with bankers and regulators necessary to get a deal done quickly. By contrast OpenAI filed its S-1 a week later (June 8, 2026) but has publicly and internally signaled a preference to delay to 2027, citing a self-imposed $1 trillion IPO floor and the desire to show additional revenue/earnings trajectory. That valuation floor plus sizable committed capital expenditures increases OpenAI’s inertia toward delaying.

Historical precedents from large private technology issuers show that confidential S-1s + a publicly stated target window are meaningful predictors of being able to list first, provided macro conditions do not suddenly deteriorate. The regulatory and underwriter processes can still produce slippage, but Anthropic’s timeline and investor support meaningfully increase its odds of execution within the near-term window. Anthropic’s ~965B private valuation puts it very close to OpenAI’s $1T target; if market reception is reasonably constructive, Anthropic can hit investor price expectations without needing to stretch into an uncertain public re-rating.

Countervailing risks exist: the live regulatory overhang on AI giants, a choppier macro/IPO market that could push deals into 2027 or later, and typical issuer caution (underwriters can recommend delay). OpenAI’s brand, scale, and deeper enterprise contracts could allow it to accelerate if Anthropic encounters unexpected issues. Also, both firms could choose to remain private for strategic reasons, or neither might list until far later based on geopolitical/regulatory developments. Those scenarios reduce the predictive certainty of any near-term outcome.

Balancing the tangible forward commitments from Anthropic against OpenAI’s explicit caution and higher valuation requirement, my independent assessment is that Anthropic has a strong lead in the race to be first. I assign a 78% probability that Anthropic will IPO before OpenAI sometime before 2040.

**Stage 2 — Market calibration (compare to current market prices):**

The current market price (Yes = 82%) is slightly higher than my independent probability (78%). The market is therefore placing marginally more weight on Anthropic’s execution or on additional downside risks to OpenAI than I am. Several explanations for the market premium make sense:

- Traders are pricing in short-term momentum and the psychological advantage of a public target month (October 2026), which often causes markets to overweight the closer-deadline issuer. - Liquidity and event-driven players may have already frontloaded positions around the June filings and the October target, compressing the market probability higher than a longer-horizon structural view would justify. - Market participants may be giving additional credit to anecdotal reporting (banker/leak confidence) or to the perceived high likelihood of underwriters wanting a marquee AI listing even in uncertain markets.

However, the market may be overconfident on two fronts: it may under-appreciate regulatory/SEC timing risk that could push an Anthropic listing beyond OpenAI’s delayed window, and it may over-discount OpenAI’s ability to adjust tactics (e.g., lower initial float, staggered secondary, or alternative listing structure) to meet the $1T target sooner than currently signaled. Given those considerations, the market is plausible but slightly overstates Anthropic's advantage by ~4 percentage points. That gap is modest; I would view prices at or above 82% as indicating crowd conviction. If Anthropic’s October 2026 cadence remains publicly reinforced (bank tentatives, roadshow leaks, anchor investor commitments), market odds of Anthropic-first are reasonable to remain elevated. Conversely, any credible regulatory delay, adverse market movement, or a sudden OpenAI tactical pivot would push my posterior probability downward and likely reset market prices quickly.

Bottom line: I view the market as close to correct but mildly optimistic about Anthropic’s ability to execute on the October 2026 timetable; my independent probability is 78% versus the market 82%.