AI Prediction Index

One prediction, on the record

CapabilitiesIncorrect
“Grok 4.20 is coming out in 3 or 4 weeks.”

CEO of Tesla, SpaceX and xAI; owner of X

Said Dec 7, 2025Deadline Jan 4, 2026Post on X by Elon Musk, 7 December 2025

Grok 4.20 missed the 3–4 week window by a wide margin: it did not reach users until a limited beta on 17 February 2026, with the full rollout and general availability following in March 2026 — roughly two to three months later than promised. (The claim that it beat GPT-5.1 and Gemini 3 Pro came from third-party Alpha Arena trading-sim reports, not from Musk.)