xAI
Founder
A frontier AI lab that built one of the world's largest supercomputers in months and ships the Grok models.
x.ai100k GPUs / 122 days
Colossus initial build
~$230B
Valuation (Series E, 2026)
July 2023
Founded
Grok 4.x
Flagship model
Musk founded xAI in July 2023 with the stated mission to "understand the true nature of the universe" and build maximally truth-seeking AI. Its Grok assistant launched in November 2023 and is integrated into X.
xAI's signature feat is raw execution: it built the "Colossus" supercomputer in a converted Memphis factory, installing 100,000 Nvidia H100 GPUs in just 122 days — a buildout that normally takes years — then expanded it dramatically toward a stated goal of a million GPUs. That compute let Grok iterate rapidly; by 2025 Grok 4 posted frontier scores on hard reasoning and math benchmarks.
xAI acquired X in a 2025 all-stock deal and, after a January 2026 Series E, was valued at roughly $230 billion — among the most valuable private companies in the world less than three years after founding.
Milestones
Grok assistant launches, integrated into X.
Colossus: 100,000 H100 GPUs installed in 122 days.
xAI acquires X in an all-stock merger.
$20B Series E values xAI at ~$230B.
Sources