OpenAI Surges 8 Cents as GPT-5.5 Launch Appears Imminent

AI prediction markets experienced one of their most dramatic single-day rotations today. The flagship 'Which company has the best AI model end of April?' market on Polymarket shows OpenAI surging from ~19 cents to 27 cents (+8), while Anthropic cratered from ~79 cents to 71 cents (-8). This is a massive swing for a market where 8 cents represents hundreds of thousands of dollars in position value given $194K and $101K in 24h volume respectively.

The catalyst appears to be GPT-5.5 release timing. The April 23 release market (0xbcf382ddb2bb0333cc) is at just 1 cent today after collapsing 8 cents — meaning traders are pricing out tomorrow as the release date. However, the April 23 market (0x3de1a705488234aeb8) at 87 cents (+5 cents) with $71K volume suggests a release around this date remains highly probable. The April 30 market (0x0f461cb384aa6289cc) sits at 93 cents (+1 cent).

The Kalshi AI markets show slightly different readings: KXLLM1-26APR25-ANTH prices Anthropic as best AI at 89 cents, while KXLLM1-26APR25-OPEN prices OpenAI at just 11 cents. This Kalshi/Polymarket divergence — Kalshi at 89/11 vs Polymarket 71/27 — represents a potential arbitrage worth examining.

DeepSeek V4 release by April 30 (0xe5883e093e642062ac) is at 79 cents (+6 cents) — another near-term catalyst that could shake the leaderboard. The June 2026 best-AI markets show Anthropic at 51 cents (-5 cents) and Google at 28 cents, suggesting a more competitive landscape by summer.

The Claude Mythos release market (0xf79fa1e99b1a05dbe1) at 2 cents by April 30 suggests Anthropic's next flagship model is NOT imminent, potentially explaining why OpenAI is gaining ground. Claude 5 by April 30 is also near zero at 1 cent.

For traders: the Kalshi KXLLM1 spread vs Polymarket represents the clearest actionable opportunity. If GPT-5.5 launches this week and is competitive, OpenAI could reach 40-50 cents on Polymarket while Anthropic resets lower.