OpenAI’s chief scientist Jakub Pachocki recently described GPT-5.6 internally as a “meaningful improvement” over the current GPT-5.5 flagship, fueling speculation of a late-June public release. Leaks in Codex traces and internal codenames have surfaced alongside reports of a 1.5-million-token context window aimed at complex codebases. Traders on prediction markets have placed over $960,000 in volume, assigning roughly 83% implied probability to a June 22–28 window amid competitive pressure from Anthropic’s Opus 4.8 and Chinese models like GLM-5.2 that have posted stronger benchmark results. OpenAI’s planned IPO filing adds urgency to maintain frontier positioning, though no official model card, benchmarks, or announcement has appeared as of June 18. Any slippage in testing or last-minute safety reviews could shift the timeline into July.