PendingMassive Grok gains in ~3 months from C/C++ stack rewrite
“Truly massive gains will come in ~3 months when the entire training and inference stack is written in C/C++…”
Elon Musk said xAI would open-source its 0.5T Grok model by the end of 2026. It hasn't happened yet, with 93 days left.
“We will open source the 0.5T model towards the end of this year. It should still be quite useful.”
— Elon Musk · May 25, 2026 · @elonmusk on X ↗
See his original post on XLoads Elon's actual tweet, right here.
Show ▾
What actually happened
Fetched Sep 20 2026: Hugging Face xai-org still lists only grok-1 (Mar 2024) and grok-2 (Nov 2025). No 0.5T / 500B Grok weights. x.ai/news has no open-source model drop since Grok-1; current flagship Grok 4.6 (Aug 12) is proprietary. GitHub xai-org still has grok-1 as the open-release model repo. Deadline end of 2026. Status stays pending. Hugging Face xai-org fetched Sep 20 2026 — grok-1 and grok-2 only; no 0.5T open weights ↗
The Progression
May 25, 2026
The promise: “We will open source the 0.5T model towards the end of this year. It should still be quite useful.” · @elonmusk on X ↗
Today · Sep 29, 2026
Status: Pending · 93 days left. Still waiting.
On May 25, 2026, replying on X, Elon Musk said xAI would open-source 'the 0.5T model' (a 500-billion-parameter Grok model) 'towards the end of this year' — an end-of-2026 target. xAI previously open-sourced Grok-1 in March 2024.
Receipts
LAST CHECKED 2026-09-20- [TWEET] @elonmusk on X
xAI’s record
Delivered
11
79% of resolved claims delivered.
Missed
3
Deadline passed, still no-show.
Read next
Also xAI, resolves soonest
PendingAlso xAI, resolves soonest
PendingColossus +220k GB300 fully operational next week
“Another 220k GB300 will be fully operational next week and another 220k in November. If we get lucky, yet a…”
Also xAI, resolves soonest
PendingGrok makes a watchable movie by end of 2026
“Grok will make a movie that is at least watchable before the end of next year and really good movies in 2027.”
/// The Daily Verdict
Know the moment a prediction lands — or doesn't.
One email a day, only when something changes: a new promise, a blown deadline, a goalpost move, or a rare on-time delivery. No spam, instant unsubscribe.
Discussion