xAI is an artificial intelligence company founded by Elon Musk on March 9, 2023, with the mission of building AI systems to accelerate scientific discovery. The company develops the Grok family of large language models, distinguished by real-time data access through integration with the X (formerly Twitter) social network. In February 2026, xAI became a wholly owned subsidiary of SpaceX in an all-stock transaction valuing xAI at $250 billion.1)
xAI open-sourced Grok-1's model weights to build trust and accelerate adoption among researchers and developers, establishing xAI's commitment to open AI development.
Released August 2024, Grok-2 and Grok-2 mini established xAI as a major AI competitor, reaching performance levels competitive with GPT-4o and Claude 3.5 Sonnet on the LMSYS Chatbot Arena leaderboard.2)
Achieved human-level math benchmarks by December 2024, representing xAI's most advanced model at the time. Grok-3 features superior reasoning capabilities combined with extensive pretraining knowledge.
The latest generation features 2-million-token context windows and advanced reasoning capabilities. In June 2025, xAI reasoning models were integrated into Tesla Optimus prototypes.3)
In March 2025, xAI acquired X (formerly Twitter) in an all-stock transaction valuing X at $33 billion and xAI at $80 billion, creating a combined entity called X.AI Holdings Corp. This provides:
xAI built Colossus in Memphis, Tennessee, completing the initial installation of 100,000 NVIDIA H100 GPUs in just 122 days (late 2024). By 2025, the cluster expanded to over 200,000 GPUs (including H200 chips), making it the world's largest concentrated AI training facility.5)
xAI completed an upsized Series E in 2026, raising $20 billion (exceeding the $15 billion target). Previous rounds include a May 2024 Series B ($6 billion at $24 billion valuation). Musk has stated the company could achieve artificial general intelligence (AGI) by 2026.7)