Arm

Seventeen months after signing, the companies terminated the agreement, citing significant regulatory challenges, and Nvidia wrote off the $1.36 billion it had prepaid. Arm listed on Nasdaq in September 2023 at a $54 billion valuation; Nvidia kept a 20-year Arm architecture licence and went on to build its own Arm-based Grace CPUs.

The Federal Trade Commission voted 4-0 to challenge the deal, arguing that owning Arm would let Nvidia stifle rivals that depend on Arm designs in data center CPUs, automotive and DPUs, and give it access to competitors' confidential information. The UK's CMA had already opened an in-depth probe on national-security and competition grounds and the European Commission a Phase 2 review.

The UK secretary of state referred Nvidia's proposed acquisition of Arm to the CMA for a Phase 2 investigation. The referral cited competition and national-security concerns.

The UK Competition and Markets Authority found that Nvidia's proposed purchase of Arm should proceed to a Phase 2 investigation. The CMA cited competition grounds for the in-depth investigation.

The largest chip deal ever proposed would have put the architecture behind nearly every smartphone under the company that dominated AI accelerators, with SoftBank keeping under 10 percent of Nvidia. Huang promised to keep Arm's open licensing model and its Cambridge headquarters; customers including Qualcomm, Google and Microsoft objected within months.