The stake traces to an early funding round, while investors have discussed a valuation of around $1.5 trillion for the AI startup.
3M expands Amazon partnership with stock warrant worth over $521 million
Most of the warrant shares will vest as Amazon purchases 3M data-center products, with that portion fully vested at $6 billion in purchases.

3M said on October 19 that it had expanded its commercial relationship with Amazon and granted a wholly owned Amazon subsidiary a warrant to buy stock worth over $521 million. The industrial conglomerate's shares rose more than 5% in extended trading following the announcement.
The warrant allows the subsidiary to purchase as many as 3.16 million shares of 3M over seven years, at a price of $164.89 each, the company said.
About 85% of the shares covered by the warrant will vest as Amazon purchases optical connectivity and other products for data centers from 3M. That portion will vest in full when purchases reach $6 billion. Vesting of the other 15% depends on specified milestones.
The expanded relationship comes as major technology companies increase data-center infrastructure spending to support growth in AI and cloud computing. In July, Microsoft became the first hyperscaler to use 3M's Expanded Beam Optics technology in its AI data centers.
