OpenAI 'Spud' pretraining rumour

A developer blog is circulating a claim that OpenAI finished pretraining a model nicknamed “Spud” on March 24, but OpenAI has not confirmed it. (abhs.in) The same post, published April 11, says the unreleased system could ship as “GPT-5.5” and cites a Polymarket contract that it says priced April 30 release odds at 78%. A live market page tracked by Yahoo Finance shows a contract tied to whether a model explicitly named “GPT-5.5” is made public. (abhs.in) (finance.yahoo.com) Pretraining is the long first pass where a model absorbs patterns from huge datasets before later stages like fine-tuning, safety testing, and red-teaming. The blog itself says those later stages still sit between a completed training run and any public launch. (abhs.in) That gap matters because OpenAI’s recent public product line is already moving quickly. OpenAI released GPT-5 on August 7, 2025, GPT-5.2 on December 11, 2025, GPT-5.3 Instant in early March 2026, and GPT-5.4 on March 5, 2026. (openai.com 1) (openai.com 2) (openai.com 3) (openai.com 4) OpenAI had also signaled a broader consolidation of its model lineup before this rumor appeared. In a roadmap post reproduced on OpenAI’s developer forum on February 12, 2025, Sam Altman said GPT-5 would integrate more of the company’s technology and reduce the need for separate model choices. (community.openai.com) Since then, OpenAI has kept shipping within the GPT-5 family rather than unveiling a clean break to GPT-6. OpenAI’s help documentation says GPT-5 models in ChatGPT were retired on February 13, 2026, as GPT-5.3 and GPT-5.4 took over, while the API docs now label GPT-5.2 as a “previous frontier model” and recommend GPT-5.4. (help.openai.com) (developers.openai.com) The strongest public evidence in the rumor chain is still thin. The “Spud” reporting comes from a single developer-focused site, and the same article presents unverified estimates about capabilities, context length, and release timing as community expectations rather than published specifications. (abhs.in) Prediction markets add another signal, but they are not company statements. Polymarket-style contracts reflect trader pricing, and Yahoo Finance’s market page defines resolution around a model explicitly named “GPT-5.5,” which means even a release of something “Spud-like” under another name would not necessarily settle the contract the same way. (finance.yahoo.com) There is also a practical reason developers are paying attention to any hint of a new model. OpenAI’s March 5 announcement for GPT-5.4 said the model added native computer use and a context window of up to 1 million tokens, and GitHub began rolling GPT-5.4 into Copilot the same day. (openai.com) (github.blog) For now, the cleanest version of the story is narrower than the rumor mill suggests: there is a published claim, there is a prediction market, and there is no OpenAI announcement of “Spud” or “GPT-5.5” as of April 12, 2026. (abhs.in) (openai.com)