Kakao, the operator of South Korea's most popular chat app KakaoTalk, has transacted 5 trillion won ($4.18 billion) over its securities app since its launch two years ago.
Securities Plus for Kakao, a mobile trading system, was launched in February 2014, and has garnered substantial users thanks to the popularity of the firm's chat app.
For Android users, subscribers to the trading app need only one registered authentication ID to use all securities services available from Kakao. In South Korea, people are required to get authentication IDs from registered banks for online transactions, and may require more than one ID for each service ranging from tax payment to securities trading, drawing criticism for being too complicated.
Kakao allows users to have just one ID to use all services provided by different securities firms that have signed cooperation agreements with the chat giant.
Dunamu, the South Korean mobile tech startup that developed the app, said Securities Plus has garnered 1 million in downloads and saw 1 trillion won traded during December last year alone.
The app also shows the highest-earning users and ranks profitable investors.
Mobile security trading is quickly rising in South Korea. According to the Korea Exchange, an average of 248.87 million shares were traded per day using the mobile trading system last year in the Korea Composite Stock Price Index (KOSPI) market -- double that of the year before. Mobile accounted for 27.33 percent of shares traded for last year.
At the Korea Securities Dealers Automated Quotations (KOSDAQ), mobile trading per day was 363.99 million shares, also double that of the year before, and accounted for 30.11 percent of total trade.
When the iPhone first arrived in South Korea in 2009, mobile trading only accounted for around 2 percent of transactions.
Kakao serviced its chat app and an accompanying mobile social network service but has since expanded into games, music, and cab chauffeuring in South Korea. The company recently got approval to form a web-based bank and is now tapping aggressively into the finance sector.
Kakao's net income dropped 80 percent for the fourth quarter last year due to investments in new businesses. It announced last month that it was acquiring South Korea's largest music streaming service, MelOn, for 1.87 trillion won.