Japan Investigates Surge in Fraudulent Trades Worth $350 Million Linked to Hacked Brokerage Accounts

Japan’s financial regulator has raised the alarm following a significant rise in unauthorised trading activity tied to compromised online brokerage accounts, totalling hundreds of millions in fraudulent transactions.

The Financial Services Agency (FSA) revealed on Friday that at least 12 securities firms had fallen victim to cybercriminals who manipulated accounts to carry out illicit stock trades. The scale of the fraud is striking: unauthorised sales reached roughly $350 million, while the purchase of mainly Chinese equities amounted to around $315 million.

Officials believe phishing schemes—disguised as genuine investment platforms—are to blame for stealing login credentials. Once access is gained, attackers swiftly liquidate existing holdings and reinvest the proceeds into foreign stocks, leaving unusual assets sitting in customer accounts.

More than 3,300 unauthorised logins and over 1,450 fraudulent transactions have been identified so far. However, the FSA cautioned that further incidents may still be undetected.

Brokerages including Rakuten Securities, Nomura Holdings, SMBC Nikko, and SBI Holdings have all reported breaches. Affected firms have pledged to reimburse clients impacted by the attacks.

The warning follows growing concerns over regional cyber activity and digital espionage. Japanese authorities have repeatedly warned of state-linked hackers, particularly from China, targeting infrastructure and telecom services. Officials from Japan’s National Centre of Incident Readiness recently underscored this concern during an international cybersecurity summit.

In response to the current wave of fraud, the FSA is urging investors to be cautious when using online trading platforms, avoid reusing passwords, and be vigilant for spoofed websites. Regulatory efforts are now focused on tightening digital security protocols across the financial sector.