It turned out that cases using nonpublic information accounted for 60% of major unfair stock transaction cases detected by the Korea Exchange (KRX) last year.
On the 11th, the Korea Exchange (KRX) said through its materials "2025 unfair transaction review results and key features" that a total of 98 unfair transaction cases occurred in 2025. While cases of using nonpublic information decreased by one from the previous year, violations of reporting obligations increased by one.
Among them, cases using nonpublic information were the most at 58 (59.2%), followed by unfair transactions at 18 (18.4%) and price rigging at 16 (16.3%).
In particular, multiple instances were found in which tender offer information was exploited for unfair gains. There were 11 cases in which a securities firm official, who was an employee or agent of the tender offeror, knew the information in advance and used a borrowed-name account or passed the information to an acquaintance to profit.
There were also unfair transactions that leveraged political issues. Four cases were counted in which the characteristics of election-related political theme stocks were abused for unfair transactions or price rigging.
Methods of unfair transactions are becoming increasingly sophisticated. A typical case involves falsely disclosing acquisition funds as own funds to obtain management control, then using factors such as large-scale financing or entry into new businesses to drive up the stock price and selling held equity to realize gains. It was also found that convertible bonds (CB) were resold to related parties at prices below market, causing losses to the company, or that funds were provided to affiliates through lending and then written down as impairments.
By market, unfair transactions appeared most actively on KOSDAQ. KOSDAQ accounted for 66 cases (67.3%), the Korea Composite Stock Price Index (KOSPI) market 28 cases (28.6%), and the KONEX market 2 cases (2%).
The average unfair gain per case is 2.4 billion won. This is a 33% increase from the previous year (1.8 billion won). However, it fell sharply compared with 2023's 7.9 billion won.
In response, the Financial Services Commission, the Financial Supervisory Service, and the Korea Exchange (KRX) established a "joint response team to eradicate stock price manipulation" and are reviewing and investigating numerous suspected unfair transaction cases, detecting large-scale stock price manipulation by high-net-worth individuals (Case No. 1), use of nonpublic information by a securities firm executive (Case No. 2), and front-running by a media reporter (Case No. 3).
The Korea Exchange (KRX) said, "Particular caution is needed when investing in issues where stock prices rise above the intrinsic value of corporations due to specific themes such as artificial intelligence (AI), robots, and secondary batteries, as well as election-related themes and marginal companies with frequent changes in control," and added, "In 2026, we will swiftly review unfair transactions through a close cooperation system with the financial authorities."