SBI Holdings CEO Yoshitaka Kitao, known as a maverick financier, dropped a bombshell in 2019 when he revealed his bold plan to scrap commission fees for domestic stock trading at his online brokerage arm.

The SBI Securities announcement shocked the industry, as such commissions have been one of the main revenue sources for a slew of securities firms — including SBI itself, which boasts the dominant share among the domestic online brokers.

But with the aim of bolstering its customer base, SBI introduced the commission-free service starting Saturday amid growing interest in investing thanks to government efforts to persuade people to shift household assets from cash and savings to investments.