Anthropic confirmed on Monday that it has filed a confidential S-1 registration form with the U.S. Securities and Exchange Commission, marking a significant step toward an initial public offering. The filing arrives just days after the startup closed a $65 billion Series H funding round, which brought its post-money valuation to $965 billion. This figure officially surpasses OpenAI’s most recently reported valuation of $852 billion, according to data reported by The Register.
Anthropic has provided minimal details regarding the potential offering, noting that the number of shares and pricing have not yet been determined. In a statement, the company emphasized that the IPO remains subject to market conditions and other variables. The move is viewed by industry observers as a strategic attempt to capitalize on its current position as the world's most valuable AI startup before its primary rival, OpenAI, can reclaim the lead.
While Anthropic moves toward public markets, OpenAI faces a significant legal challenge from the state of Florida. On Monday, Florida Attorney General James Uthmeier announced an 83-page lawsuit against OpenAI and CEO Sam Altman, the first state-led litigation of its kind against the company. The suit alleges that OpenAI prioritized winning the "AI arms race" and accumulating wealth while ignoring internal and external warnings regarding the safety of its products.
Attorney General Uthmeier stated that the company’s "misrepresentations" regarding ChatGPT have facilitated numerous harms, including mass shootings, encouragement of suicide, and the loss of critical thinking skills among users. The lawsuit specifically points to a criminal investigation launched by the Florida Attorney General’s office in April, which examined the role of ChatGPT in a 2025 mass shooting at Florida State University. The state alleges that the shooter consulted the chatbot prior to the attack.
OpenAI has consistently denied responsibility for these violent incidents. Regarding the Florida State University tragedy, an OpenAI spokesperson previously told NBC News that “ChatGPT is not responsible for this terrible crime.” The company’s legal team has also recently navigated a civil suit filed by former co-founder Elon Musk, which was dismissed by a jury that determined Musk had waited too long to file the action, citing the statute of limitations.
The Florida lawsuit seeks to hold the company accountable under state laws governing unfair trade practices, product liability, and public nuisance. Uthmeier expressed his intent for the litigation to force a shift in industry programming, noting, “I hope and expect other states will follow and ultimately we need [AI companies] to change their programming.”
For now, the contrast between the two firms remains stark. Anthropic is positioning itself for a transition to public ownership, banking on the current market sentiment toward AI. Conversely, OpenAI remains mired in a complex legal battle that questions its foundational safety protocols and corporate governance. As the SEC reviews Anthropic’s confidential filing, the outcome of the Florida lawsuit may introduce new regulatory scrutiny that could impact the broader AI sector.
