Toss Securities CEO Kim Seung-yeon resigned abruptly Thursday, six months before the end of his term. The firm's head of product, Kim Gyu-bin, was appointed as his successor during a general shareholders' meeting earlier in the day.

Kim Seung-yeon, appointed to serve from April 2023 until April 2025, stepped down for "personal reasons," according to the company, which is the brokerage arm of fintech giant Toss.

With his appointment, Kim Gyu-bin, 35, became the first securities firm CEO in South Korea to take the helm in his 30s. An engineer-turned-entrepreneur, Kim joined Viva Republica, the operator of Toss, in 2020 after earning a degree in electrical and computer engineering from Carnegie Mellon University and gaining experience in tech-based service planning at eBay Korea.

Since joining Toss Securities in January 2022 as a product owner, Kim has led key innovations, including the launch of real-time fractional overseas stock trading and boosting the platform’s investor community.

Toss Securities emphasized he played a pivotal role in helping the firm achieve its first quarterly profit in the third quarter of 2023, which was followed by its first annual profit— a milestone for Viva Republica affiliates.

Recently, the online brokerage has been expanding its services, launching overseas bonds, diversifying its offerings and introducing web-based trading via Toss Securities PC. Since its March 2021 launch, the firm has grown rapidly, reaching 6.3 million customers by September. Building on its strength in overseas stock brokerage, it has recently expanded its focus to cater to both novice investors and professional traders.

Along with Kim’s appointment as CEO, Product Owner Ko Dong-won was named the new head of product Thursday.