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Backup system set to 'off' caused full-day Tokyo Stock Exchange shutdown

An electronic board of a securities firm in Osaka's Chuo Ward is seen without share prices due to a glitch at the Tokyo Stock Exchange that halted trading of all listed shares, on Oct. 1, 2020. (Mainichi/Yoshiyuki Hirakawa)

TOKYO -- Tokyo Stock Exchange (TSE) trading ground to a halt for a full day after a technical glitch because the switchover to the backup system had been set to "off," the bourse revealed on Oct. 19.

    The TSE said there was an error in the manual of Fujitsu Ltd., which supplied the equipment, and that the exchange had been unaware of the problem for the five years since the system was last updated. If the switchover to the backup had been set in the "on" position, the auxiliary system would have kicked in immediately to avert the Oct. 1 outage.

    According to the exchange, the glitch in the main system was triggered by a malfunction in a shared storage device that records information necessary for operating the trading system.

    Until the specifications for the system were changed in September 2015, the backup system had been set to take over 15 seconds after the main system went down, even if the switchover was set in the "off" position. However, the U.S. firm that manufactured the apparatus changed the settings so that the backup system would not activate when the switchover was set to "off."

    Fujitsu was unaware of the change and delivered the system to the TSE with the backup switchover left off. Furthermore, Fujitsu failed to specify the on/off control for the backup system in its manuals, so the TSE apparently did not notice the change until the catastrophic system freeze.

    The bourse has submitted a report including the problem's cause and measures to prevent a recurrence to the Financial Services Agency. The agency will look into imposing administrative penalties on the TSE including a business improvement order.

    The TSE has set up a panel comprising securities companies, investors and other parties to examine steps to prevent the problem from happening again. The panel will start discussions on setting clear criteria for circuit breakers and resumption of trading, among other issues, as early as this month.

    (Japanese original by Atsuo Yamaguchi and Koki Mikami, Business News Department)

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