Anthropic and OpenAI financiers chase prime credit ratings ahead of blockbuster IPOs

Anthropic and OpenAI both filed confidential S-1 registration statements with the SEC in June 2026, setting the stage for what could be the most consequential tech IPOs since, well, ever. Behind the scenes, the financial machinery is even more interesting than the filings themselves. Major private credit firms and Wall Street banks are assembling enormous debt structures around both companies, with the explicit goal of securing investment-grade credit ratings that would make these AI ventures look less like moonshots and more like blue-chip infrastructure plays. The numbers behind the curtain Anthropic, the maker of the Claude AI models, filed its confidential S-1 on June 1. OpenAI followed a week later on June 8. Both companies are eyeing valuations north of $850 billion, with the upper end stretching past $1 trillion. Anthropic closed a staggering $65 billion Series H funding round in late May 2026, which pegged its post-money valuation at $965 billion. Apollo Global Management and Blackstone have finalized a structured notes package worth approximately $35 to $36 billion, designed specifically to finance AI chip procurement for Anthropic. Those notes received mid-investment-grad...