After starting its journey at $ 56.10 (+10%), the share took up to 30%, before closing at 63.59, 24.69% more than the $ 51 retained Wednesday by Arm as an IPO price. The latter was already at the high end of the initial range of $47 to $51.

Thursday, after the bell, the British flagship was valued at $ 65.2 billion, and even $ 67.9 billion counting the securities allocated to employees and managers.

The first day of trading often sets the tone for a company's stock market performance during its first months on the market.

This is the largest IPO in the world since November 2021 and the arrival on Wall Street of the electric vehicle manufacturer Rivian, valued at $ 77 billion, at the time.

This is a victory for Masayoshi Son, boss of SoftBank Group, majority shareholder of Arm, who had been deemed too greedy to have targeted a valuation between 60 and 70 billion.

The success of the introduction of Arm represents a form of redemption for the Japanese entrepreneur, who has been mainly talked about, in recent years, for his colossal losses recorded on technological investments.

In particular, SoftBank has suffered several billion dollars in losses on its stakes in the fallen king of shared offices WeWork as well as in the capital of the Chinese giant of online commerce Alibaba.

At the origin of this reintroduction, SoftBank has chosen to dispose of only about 10% of the capital, and has already recovered $ 4.8 billion, a total that could go up to $ 5.2 billion if exercised the over-allotment option, which allows intermediary banks to acquire additional securities.

This places the deal as the 17th largest IPO ever conducted in the United States.

SoftBank keeps 90% of the shares

As for the balance of shares, Masayoshi Son said Thursday on CNBC that he intends to keep it. "I want to keep as much as I can, as long as possible," he said.

The fact that SoftBank retains ownership of about 90% of the securities could make Arm a volatile stock market value, where it is more difficult to find a seller or buyer when the free float (number of shares outstanding) is limited.

"We are thrilled to go public today, happy for all our employees, partners and developers," Arm CEO Rene Haas said on CNBC.

This is a return to listing for Arm, which has already made a first gallop on the stock market from 1998 to 2016, before its takeover by SoftBank, for $ 32 billion.

Arm's baptism of fire was also a full-scale test for the IPO market, weighed down by central bank monetary tightening and tighter credit conditions.

You have to go back to 1990 to find lower figures than the 2022 vintage.

"It's been 18 months since we've had a real IPO, and it's a success," said Art Hogan, an analyst at B. Riley Wealth Management.

To ensure the success of the project, Arm had secured the support of a group of prestigious customers, from Apple to Nvidia, ready to invest $ 735 million in its capital.

Behind Arm, are already announced on the New York square the shopping delivery platform Instacart, the online marketing specialist Klaviyo, as well as the manufacturer of the famous sandals Birkenstock, whose file was officially filed Tuesday.

© 2023 AFP