AI OpenAI Eyes 2027 IPO Delay As Washington Clears Anthropic's Mythos 5 By Sandy Carter ,
Forbes contributors publish independent expert analyses and insights. Sandy Carter, COO at Unstoppable, Top 10 Microsoft MSN AI Entrepreneur Follow Author Jun 28, 2026, 12:12am EDT Jun 28, 2026, 12:50am EDT --:-- / --:-- This voice experience is generated by AI. Learn more . This voice experience is generated by AI. Learn more . Summary OpenAI and Anthropic are defining the next phase of AI, both pursuing near $1 trillion valuations. OpenAI is reportedly delaying its IPO to 2027, despite filing a confidential S-1 and launching ChatGPT ads. Anthropic, however, recently surpassed OpenAI's private valuation at $965 billion and filed its own S-1. Concurrently, Washington is asserting significant control; Anthropic's advanced models, Mythos 5 and Fable 5, faced suspension, with only Mythos 5 later cleared for vetted US organizations. OpenAI also agreed to phase its GPT-5.6 rollout at government request. This demonstrates that government oversight is now rapidly shaping the trajectory and accessibility of frontier AI models.
OpenAI and ANthropic, two of the top AI LLM model creators, are deciding on IPOs and are dealing with government restrictions. (Photo by Imen Ben Youssef / Hans Lucas / AFP via Getty Images) Hans Lucas/AFP via Getty Images OpenAI and Anthropic spent June proving they are the two labs that will define the next phase of AI, and the month closed with both still moving toward listings near $1 trillion while Washington asserted fresh control over their most powerful models.
Per CNBC , OpenAI is leaning toward delaying its IPO, Anthropic just overtook it on private valuation, and on June 27 the US government decided which of Anthropic 's frontier models could return and on what terms. The Big Two are scaling faster than any companies before them, and Washington is now part of the story.
OpenAI signaled this week that it would rather wait. The New York Times reported on June 26 that OpenAI is leaning toward a 2027 listing, easing off a plan to go public as soon as the fourth quarter of 2026, after SpaceX's record IPO cooled and the broader tech market softened.
The company filed a confidential S-1 on May 22 with Goldman Sachs and Morgan Stanley, and Sam Altman has refused to trim the $1 trillion target, a steep climb from the $852 billion mark set when its record $122 billion round closed in March.
Amazon's money sets part of the clock: $35 billion of its commitment unlocks only when OpenAI goes public or reaches AGI, so a long delay carries real cost, and CFO Sarah Friar has told colleagues the company may not be ready, according to the Wall Street Journal .
To widen the base it eventually prices against, OpenAI now sells ChatGPT ads, a business it declared at Cannes Lions, where the US pilot already passed $100 million in annualized revenue on a path the company pegs at $100 billion by 2030 per Reuters .
Anthropic chose this moment to pull ahead on paper.
The company raised at a $965 billion valuation in late May, overtaking OpenAI's private mark for the first time, then filed its own confidential S-1 on June 1. Both filings landed within ten days of each other, a sign the IPO window cracked open by SpaceX is the one every lab is watching.
Anthropic has passed OpenAI in valuation. (Photo by JOEL SAGET / AFP via Getty Images) AFP via Getty Images That puts the Big Two on parallel tracks, with An…