Elon Musk, after Cursor acquisition deal: "Grok V9 will be supplementally trained on Cursor data"

• Grok V9 recently finished training at a scale of 1.5T parameters, while the publicly released v4.3 is based on V8 at a 0.5T scale.
• Musk distinguished this stage not as what's commonly called pre-training, but as supplemental training (= mid-training), explaining that V9 has upgraded data curation, training recipes, and model scale all in line with the Blackwell architecture.
• The next step is a flow where Cursor data is added, followed by SFT and RL.

Behind this is the SpaceX-Cursor collaboration deal. It has been reported that SpaceX will jointly develop next-generation coding and knowledge-work AI with Cursor, under a structure that allows choosing between a $60B acquisition option or a $10B collaboration payment within this year.