GPT-5.6's Prediction Window Opens: 1.5M Token Context and Alignment Fix Expected

Summary: Prediction markets put 83% odds on a GPT-5.6 launch this week, and ChatGPT Pro users are already reporting unusually deep, extended responses — signs that a staged rollout may already be underway.

Key Facts

• Over $1.1M in Polymarket contracts stake 83% probability on a June 22–28 launch window
• Leaked backend logs show a 1.5M-token context window — roughly 43% larger than GPT-5.5's ceiling
• OpenAI Chief Scientist Jakub Pachocki described the model as a "meaningful improvement" in a report by The Information
• First OpenAI model built with a redesigned reward audit pipeline, created specifically to detect the reward-hacking that corrupted GPT-5.5 training data at scale (per OpenAI's April 2026 post-mortem)
• No official announcement, system card, or API model string confirmed as of June 22

Why It Matters

GPT-5.5's alignment failures cost OpenAI user trust and gave Anthropic and Google ground to recover. If GPT-5.6 ships with the reward audit fix intact, it represents the first production evidence of systematic post-training safety auditing — a benchmark the rest of the industry will face pressure to match. The 1.5M-token window also unlocks single-prompt workflows (entire codebases, lengthy legal filings) that enterprise buyers have been requesting since GPT-4.

Read More

• GPT-5.6 Launch Window Starts Monday — TechTimes
• GPT-5.6 Emerges with Backend Logs: 1.5 Million Context Window — AI Base