OpenAI has launched GPT-5.5, outperforming GPT-5.4 and available to paid ChatGPT users. The release locks in a 100% YES probability for GPT-5.5’s release by both the April 30 and June 30 2026 deadlines.
## Market reaction
The confirmation surprised no one. Both the April 30 and June 30 markets had already sat at 100% YES. The April 23, 2026 market also reads 100% YES, up from 84% a week ago.
The June 30 market has volume at $20,466 in daily USDC, while the April 30 market trades $30,936. The largest price move was a 3-point drop at 5:37 PM. These markets are flat under full confidence.
## Why it matters
GPT-5.5’s release confirms what traders anticipated given OpenAI’s pattern of incremental model updates. No bearish signals appeared in the lead-up: no delay announcement, no competing model outperforming GPT-5.4. The payout profile is now irrelevant, with no room for speculative gains in a market priced at 100% YES.
## What to watch
GPT-5.5 is out, so attention shifts to what comes next. Any announcements about GPT-6 could create new Polymarket contracts and trading opportunities around OpenAI’s release cadence.
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