Customers of 128 credit unions across Japan’s Tokai region were unable to withdraw cash, deposit funds, or complete over‑the‑counter transactions on Monday after an equipment malfunction at the Shinkin Joint Center disrupted the network. The outage unfolded as Japan’s benchmark Nikkei 225 index slumped 7%, part of a wider sell‑off in AI‑related equities that also saw South Korea’s KOSPI fall 6%.

Cause and timeline of the disruption

According to Protos, the failure was traced to an “equipment malfunction” within the Shinkin Joint Center’s processing infrastructure, not a cyber‑attack. Initial reports suggested that services would remain down for the remainder of the day, but most banks managed to restore functionality by 7 p.m. JST.

Market context: AI stock sell‑off

The outage occurred amid a sharp correction in AI‑centric stocks, which has been linked to concerns that a Democrat‑led U.S. administration could slow the development of AI research centers. Analysts cited the potential postponement of Anthropic’s planned public listing as a catalyst for the sell‑off. The broader market impact was significant, with Wall Street losing an estimated $3.2 trillion in AI‑related equity value.

Comparative incidents and broader implications

This incident follows a similar disruption in the United Kingdom, where a power event at a London‑based Google Cloud data center halted ATM withdrawals, card payments, and even crypto trading for several banks. Both cases underscore the vulnerability of financial services to non‑cyber technical failures, raising questions about resilience and contingency planning for critical banking infrastructure.

What to watch next

Regulators may scrutinize the operational safeguards of shared banking platforms like the Shinkin Joint Center, especially as market volatility spikes. Investors will be monitoring whether the AI sector stabilises after the recent sell‑off and how any policy shifts in the United States could further affect sentiment.