The Arm IPO was priced on September 13, 2023, and its American Depositary Shares (ADSs) began trading on the Nasdaq Global Select Market on September 14, 2023, under the ticker symbol "ARM." The IPO was expected to close on September 18, 2023, subject to customary closing conditions.

In summary:

• IPO pricing date: September 13, 2023
• IPO trading start date: September 14, 2023
• IPO closing expected: September 18, 2023

This was one of the biggest IPOs of 2023, with 95.5 million ADSs priced at $51 each, giving the company a valuation of about $54.5 billion.