Why it matters. Investment-tip scams run through messaging apps are a global phenomenon, and Korea's surge shows how quickly fraud migrates from phone calls to social platforms as markets rally.
Background. Korea's banking sector is concentrated among five giants (KB Kookmin, Shinhan, Hana, Woori, NH Nonghyup), so their data offers a near-nationwide picture. "Stock leading rooms" are chat groups where self-styled gurus push paid stock tips; many are fronts for fraud. Korea has a specialized law for reimbursing telecom-fraud victims, which regulators recently stretched to cover investment scams.
What to watch next. Pressure is building for new legal authority that would let banks pre-emptively block suspicious transactions before victims even file a report.
Investment Scams Drive a Surge in Frozen Accounts
South Korea’s five largest banks suspended payments on nearly 150,000 accounts linked to financial fraud over the past year, as a booming stock market fuels a new wave of investment scams even while traditional phone-based fraud declines. The figure, covering May 2024 through the end of May 2025, was reported on June 3 by the local financial industry.
According to industry data, the five banks — KB Kookmin, Shinhan, Hana, Woori, and NH Nonghyup, which together dominate Korea’s retail banking market — froze a combined 149,176 accounts after receiving reports of fraud-related losses. From November 2024 through May 2025, freezes ran at 12,000 to 15,000 cases per month. In the first five months of 2025 alone, the banks halted payments on roughly 72,000 accounts — more than double the figure of about 32,000 in the same period a year earlier.
What Is Driving the Spike
The main culprit, bankers say, is a rise in so-called “stock leading rooms” (jusik leading-bang) and other investment scams. These are chat-based groups — often run on messaging apps — where fraudsters posing as expert tipsters lure victims with promises of guaranteed stock returns, then steal their money. “With the recent stock market boom, reports of damage related to investment scams such as leading rooms appear to have increased further,” one bank official said.
A payment suspension is a reactive measure: once a victim reports a loss, or there is reasonable suspicion of fraud, banks can immediately freeze the receiving account and any linked pass-through accounts without the account holder’s consent. In 2024, Korea’s financial regulator issued guidance clarifying that investment scams — not just voice phishing — fall under the country’s law on reimbursing telecommunications-fraud victims, expanding the grounds for such freezes.
Detection Lags as Scams Grow More Sophisticated
While after-the-fact freezes have soared, the banks’ own real-time Fraud Detection Systems (FDS) are catching less. Temporary blocks triggered by FDS fell to 46,154 cases in the first five months of 2025, down 21 percent from 58,609 a year earlier.
Bankers attribute the gap to weak legal footing and increasingly manipulative tactics. “For new types of phishing crime, there is no clear legal basis for financial firms to take pre-emptive temporary measures, so it is hard to act aggressively,” an official said, adding that fraudsters often “gaslight” — psychologically control — victims, making them resist the banks’ attempts to intervene.
The trend underscores a shift in Korea’s fraud landscape. Voice phishing, long the dominant scam, is in retreat: regulators logged 9,353 cases between October 2024 and April 2025, down 35.5 percent from 14,461 a year earlier. The threat has not shrunk — it has simply moved to the stock market.
