The probability of “GPT-5.6 will not be open to the public before June 28” on Polymarket rises to 78%, up 67% in the past 24 hours.

The probability of Polymarket's "GPT-5.6 will not be open to the public before June 28" has risen to 78%, up 67% in 24 hours.

On June 11, OpenAI Chief Scientist Jakub Pachocki described GPT-5.6 as a significant upgrade over GPT-5.5 in an internal memo. Analysts believe that previous leaks regarding the Codex backend in May, along with the rapid iteration pace since the release of GPT-5.5 on April 23, have reinforced market expectations for the imminent launch of GPT-5.6.

The rules specify that GPT-5.6 includes not only models explicitly named GPT-5.6 but also models identified by OpenAI as direct successors to GPT-5.5 (such as GPT-5.7, GPT-5.8, etc.). Task-specific models, cost-optimized versions like Nano/Mini, and o series inference models are not included in the scope of this event, nor do flagship next-generation models such as GPT-6 qualify. Eligible models must be officially open to the public, including open beta or open waitlist forms. Versions limited to closed testing or private access do not meet the settlement criteria.

This event will use official OpenAI announcements and information from their official website as the main basis for settlement, supplemented by verification from reputable media reports.