Sources: UK PM Rishi Sunak met Arm CEO Rene Haas and Masayoshi Son to revive efforts to secure a London listing for Cambridge-based Arm's IPO alongside New York
Officials and London Stock Exchange face uphill battle to secure UK role for chip designer's IPO
Context & Ripple Effects
Arm's London question has been open since SoftBank paused discussions about a UK listing last summer, citing political turmoil and leaning toward a straightforward US float. Liz Truss then prepared a last-ditch bid to persuade SoftBank before her premiership collapsed, leaving the dual-listing idea dormant.
Rishi Sunak's meeting with Arm CEO Rene Haas and Masayoshi Son revives that effort at the highest level — notable because Haas had already laid out post-IPO plans for M&A and hiring that assume momentum from the float, making the venue decision consequential for Cambridge as well as for the London Stock Exchange.
First-order effects
- SoftBank faces renewed pressure to structure Arm's IPO with a London component alongside New York, reversing the simpler all-US path it drifted toward after pausing UK talks.
- The London Stock Exchange gets a second chance at the deal after Truss's bid stalled, with the pitch now running through Downing Street rather than just exchange officials.
Second-order effects
- If a London leg is secured despite the objections some UK officials and SoftBank staff have raised about FCA rules, cost and inflexibility, expect immediate pressure to simplify UK listing regimes so the concession isn't seen as a one-off favor.
- If the meeting fails, New York takes the entire IPO and criticism of UK institutional investors' grasp of tech — already voiced by domestic VCs — hardens into a standing argument against London for future chip and software floats.
Third-order effects
- Two consecutive prime ministers personally lobbying over a single chip designer's listing points to marquee tech IPOs being treated as instruments of national industrial strategy rather than ordinary exchange business.
- The episode sets up a recurring test of whether London can retain deep-tech issuers against US exchanges, with listing-rule reform likely to become the lever policymakers reach for either way.
The trend: UK prime ministers are increasingly intervening directly to keep flagship technology listings in London as New York consolidates its pull on cross-border IPOs.