By Agence France-Presse
In its opening price in Tokyo, shares in SoftBank Corp traded at 1,463 yen ($13), down from the 1,500 yen IPO price.
The blockbuster IPO is seen as part of SoftBank boss Masayoshi Son's strategy of transforming from a Japan-based telecoms company to a global hi-tech investment firm.
The IPO will help raise cash for Son, whose SoftBank Vision Fund is worth an estimated $100 billion and has taken stakes in some of the hottest tech firms, including Uber, Slack, WeWork and Nvidia.
The offering comes after an embarrassing episode last month when tens of millions of SoftBank and UK mobile phone operator O2 customers were unable to access data due to a glitch with software made by Sweden's Ericsson.