Brexit “idiocy” is partly to blame for Arm’s decision to choose New York over London for its stock market listing, but a secondary listing in the UK at a later date would make sense, according to a co-founder of the Cambridge-based chip designer. Arm’s parent, the Japanese conglomerate SoftBank, has officially filed for a US-only listing, in a blow to the UK government, which has lobbied hard for a London listing. Arm aims to raise $10bn (£8bn) and could achieve a valuation of between $30bn and $70bn in what is likely to be one of the biggest US floats this year, Arm’s co-founder Hermann Hauser said, adding that it would have struggled to raise this amount of money in the UK. “Softbank really needs the money to further support the growth of Arm,” he said. Speaking on BBC Radio 4’s Today programme, he explained why in his view the business had decided against a dual listing in London and New York. “The problem is, to IPO on two stock exchanges at the same time is an enormous amount of work, so the administrative effort is double,” he said. “The fact is that New York of course is a much deeper market than London, partially because of the Brexit idiocy the image of London has suffered a lot in the international community.” Softbank said on Saturday it had submitted a draft registration statement for the listing to the US Securities and Exchange Commission. Hauser is an Austrian physicist who holds a doctorate from Cambridge University and helped set up Arm in 1990 after his first venture Acorn, which made the successful BBC Micro computer. Now a venture capital investor in a series of UK tech companies, Hauser sold his shareholding in Arm in 2016 when it was bought by SoftBank for £24bn in 2016. “Arm is a UK company, arguably one of the more globally successful technology companies in the UK, and there is a lot of support in the London City for Arm,” he said. “It would make a lot of sense for Arm to at least have a secondary listing on the London Stock Exchange eventually.” Arm designs the technology behind microchips, or processors, which power devices ranging from smartphones to washing machines and televisions. The design has become a “global monopoly”, Hauser argued but he cautioned: “The British semiconductor industry on the hardware side is not comparable to the American, Chinese or even European semiconductor industry. Sadly we lost that during the Thatcher era when we decided not to support Ferranti and others.”