GPT-5.6 released on 2026?

Platform comparison

Market context

OpenAI has already announced GPT-5.6 Sol, with a preview launch on 26 June 2026, but has not confirmed a general-availability date for the public. The model is currently restricted to a small group of trusted partners via the API and Codex, excluding ChatGPT entirely during this phase. While the company states broader access will follow in the coming weeks, no firm timeline exists, leaving the crowd-implied probability of a public release before July 2026 at 0% on this specific market.

Historical precedents show that OpenAI frequently delays public rollouts after initial previews, often citing regulatory or safety reviews. For instance, GPT-5.5 saw a three-week gap between its internal surfacing and public release, yet markets have repeatedly misjudged such windows. Polymarket previously priced a June 30 release at 89%, a signal that diverges sharply from Kalshi’s binary odds structure and Betfair’s decimal pricing. These platforms also differ in fee models and KYC thresholds, with Kalshi requiring US residency and strict identity verification, whereas Polymarket and Smarkets offer more accessible entry for global traders.

Traders should monitor OpenAI’s official announcements, Codex backend logs, and any updates to the Deployment Safety Hub for version-bump confirmations. A recent leak spotted a routing entry for GPT-5.6 in Codex logs, suggesting the model is technically ready but not yet publicly accessible. With the settlement window ending 31 July 2026, the key catalyst is whether OpenAI expands access beyond partners before that date. As competition with Anthropic intensifies, price cuts and faster deployment may accelerate, but no official schedule has been published.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares GPT-5.6 released on 2026? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.