Will OpenAI's valuation hit (HIGH) $900B by December 31?

Prediction markets put the probability at 90%: Will OpenAI's valuation hit (HIGH) $900B by December 31. Currently, markets see this as likely (90% YES). Anthropic Hits $965B Valuation, Overtakes OpenAI as Most Valuable AI Startup.

What’s Happening

The competitive backdrop for whether OpenAI's valuation hit (HIGH) $900B by December 31 shifted materially on May 28, 2026, when rival Anthropic closed a $65 billion Series H round at a $965 billion post-money valuation, leapfrogging OpenAI to become the most valuable private AI startup. The round nearly tripled Anthropic's $380 billion valuation from roughly three months earlier and drew participation from chip manufacturers, underscoring how the AI funding cycle has consolidated around compute infrastructure. Annualized revenue at Anthropic crossed $47 billion in May, up from $30 billion earlier in the year and $10 billion twelve months prior. [OpenTools, May 31]

Pricing pressure on OpenAI intensified after PitchBook published research on June 5 classifying the company as the most expensive AI peer on a quality-adjusted basis ahead of its planned public listing. Investors are paying a steep premium relative to underlying business fundamentals, the report concluded, though headline market capitalization remains elevated. In April, OpenAI renegotiated its revenue-sharing agreement with Microsoft, capping payments at $38 billion through 2030 and preserving an estimated $70 billion to $97 billion in cash that would otherwise have transferred to its largest backer. The restructuring removed a major overhang ahead of any tender offer or secondary transaction that would mark a new primary valuation. [Morningstar, Jun 5]

The question of whether OpenAI's valuation hit (HIGH) $900B by December 31 now sits alongside an unusually active AI IPO calendar. Anthropic filed confidential paperwork with the SEC on June 1, 2026, formally entering one of the most anticipated debuts in years and intensifying scrutiny of comparable private marks across the sector. OpenAI is itself moving toward a public listing, with PitchBook flagging its peer-group premium as the central pricing risk. Near-term catalysts include any disclosed secondary tender, additional primary funding announcements, and updated revenue disclosures tied to IPO filings; each would directly reset the reference point against the $900 billion threshold before year-end. [Forbes, Jun 1]

Traded on Polymarket — $51K Volume

Lower-volume market on Polymarket ($51K). Wider spreads expected — enter with limit orders and be aware of slippage risk. Currently 90c YES.