British semiconductor and software design company
Arm is a Cambridge-founded, globally deployed semiconductor intellectual property company whose energy-efficient CPU, GPU, and system architectures power more than 280 billion chips across smartphones, data centres, automotive, IoT, and increasingly AI accelerators.
Founded in 1990 as Advanced RISC Machines, a joint venture between Acorn Computers, Apple, and VLSI Technology, Arm licenses its instruction set architecture and processor designs to more than 1,000 partners including Apple, Qualcomm, NVIDIA, Amazon, MediaTek, and Samsung.
After being publicly listed on the London Stock Exchange and NASDAQ from 1998 to 2016, Arm was acquired and taken private by SoftBank Group in 2016 in a £24.3 billion transaction. SoftBank relisted Arm Holdings plc on NASDAQ in September 2023 at a roughly $54 billion valuation.
Although Arm's operational heart remains Cambridge and the UK, the group's ultimate English parent, Arm Holdings plc, and its US listing combine to create one of the most closely watched UK-US corporate cross-listings of the decade.
Arm's corporate history is a rare example of a UK-incorporated public company that delisted from the LSE, reorganised under foreign private-equity ownership, and then relisted on a US exchange while retaining UK incorporation. The listing vehicle is Arm Holdings plc, a public limited company incorporated in England and Wales and admitted to the Nasdaq Global Select Market in September 2023.
The plc itself is a relatively recent restructuring entity, established to sit above the historic operating company Arm Limited (Companies House number 02557590) and the wider global group.
SoftBank Group retains roughly 90% of the plc's shares post-IPO, making Arm technically a controlled company under Nasdaq rules; UK company law, by contrast, still requires the plc to comply with Part 15 of the Companies Act 2006, file accounts at Companies House, and publish a UK-style annual report in addition to its US SEC filings on Forms 20-F and 6-K.
Governance is therefore a hybrid: UK company-law obligations including directors' duties under section 172, combined with US proxy, audit-committee, and related-party-transaction rules. The separation of Arm China, a partially independent joint venture, has also been prominent in Arm's disclosures; governance disputes around that entity drove specific UK filings and risk factors in the 2023 IPO prospectus.
For readers researching UK companies, Arm Holdings plc is a key example of how a UK public company can be listed on a foreign exchange while still being governed by the Companies Act.
Arm Holdings plc is listed on the Nasdaq Global Select Market under the ticker ARM, following its September 2023 IPO; the group was previously listed on the LSE and Nasdaq from 1998 until SoftBank took it private in 2016.
Yes. Arm Holdings plc is incorporated in England and Wales and the core operating company, Arm Limited, remains registered at Companies House under number 02557590; the HQ campus is in Cambridge.
SoftBank Group Corp. owns approximately 90% of Arm Holdings plc following the 2023 IPO, making Arm a controlled company under Nasdaq listing rules.
SoftBank publicly cited deeper US capital markets, US investor familiarity with semiconductor companies, and regulatory considerations; the choice fed into UK policy debates that contributed to the FCA's 2024 listing-regime reforms.
