OpenAI and Anthropic race to IPO before AI hype peaks; timing and valuation critical.
On CNBC's Closing Bell Overtime, the conversation returned to a question every AI investor is asking aloud: When do OpenAI and Anthropic stop pretending they want to stay private?
The reporters laid out a clock driven by revenue physics. Anthropic's revenue is up roughly 4x from last year, while OpenAI's run rate has doubled over the same period. Per analyst Kate Luria, these growth rates represent "the fastest right now that they will ever be." Polymarket traders agree the window is opening. The crowd assigns a 77% probability to Anthropic going public by December 31, 2026, and a 23.5% probability to OpenAI listing by the same date. For most investors, public-market proxies offer the primary way to trade this story for now.
Luria's point captures the whole game: a company with quadrupling revenue can sell a clean compounding narrative. However, a company growing 60% off a bigger base must explain the deceleration—and deceleration is where multiples die.
Anthropic confidentially filed its draft S-1 on June 1, 2026, shortly after a $65 billion funding round that valued it at $965 billion. OpenAI followed with its own confidential S-1 on June 8, with underwriter targets near $1 trillion. Being first matters in a way that is easy to overlook. Whoever lists first sets the GAAP and accounting standards Wall Street analysts will use to evaluate the entire sector, leaving the second mover to spend its roadshow defending someone else's definitions.
OpenAI carries the added burden of being the bigger spender. OpenAI is responsible for $3.1 billion in investment losses flowing through Microsoft's books in Q1 FY2026 alone.
PitchBook's Harrison Rolfe flagged the obvious risk: Google, Microsoft, and Amazon have the ability to "stiffarm and then undercut OpenAI and Anthropic on price." These same firms also represent the cleanest way to own the buildout.
Microsoft owns 27% of OpenAI in a stake valued near $135 billion. OpenAI is contractually obligated to spend $250 billion in incremental Azure services. Satya Nadella told investors the AI business surpassed a $37 billion annual revenue run rate, up 123% year-over-year in the most recent 10-Q. Microsoft's stock, however, is down 22% year to date, with retail traders on Reddit openly debating whether leadership is "incinerating capital."
Amazon booked $16.8 billion in pre-tax gains from its Anthropic stake in Q1 2026 and guided to roughly $200 billion in capex this year. Alphabet co-invests in Anthropic while running Gemini against it—a posture that helps explain why Cloud backlog crossed $460 billion. NVIDIA sells picks and shovels to all of them, with Data Center revenue of $75.25 billion, up 92% year-over-year.
The segment host drew a parallel that should give IPO speculators pause: SpaceX's offering "was super aggressive" on valuation and has "kind of flatlined since." Both OpenAI and Anthropic are reportedly reserving allocations for retail investors, but replicating "the Musk effect is obviously its own thing" for Sam Altman and Dario Amodei. Webull and similar retail venues find themselves in an interesting position. Webull launched single-company SPVs through Monark Markets in June for accredited investors seeking pre-IPO exposure, and the FINRA pattern-day-trader rule change took effect June 4, 2026. Webull stock is down 19% year to date.
The forcing function here is competitive rather than financial. Both companies have the cash they need. What they lack is the willingness to let the other file first. The timing of these filings will set the comparable multiples for every private AI lab still raising at venture rounds.
If Anthropic prices first on a quadrupling revenue narrative, every Series E pitch deck in Silicon Valley resets to that bar. If OpenAI prices first with larger absolute revenue and heavier capex commitments, the conversation shifts to scale economics and the durability of the Microsoft relationship. Either way, the public comps that matter most are already trading.
Watch the prospectus amendments through the fall, and watch whether Polymarket's probability of no OpenAI IPO by year-end starts compressing as bankers leak timelines into August earnings calls. Watch the hyperscaler capex commentary on the next round of prints, because any softening in Microsoft's or Amazon's 2027 capex framing would give IPO bears their first real data point.