Lift of SBI Japannext Trading Halts And Explanation From CIO
We deeply apologize for any inconvenience caused by today’s emergency trading halt of twelve instruments at our venue.
We have verified that the root cause of the incident was from a previously unused feature of self-trade prevention. This meant that market data was displayed incorrectly and stale images of eliminated orders remained in the market data feed. The exact QA testing pattern responsible for triggering this was not adequately covered by our QA process.
Once we identified this issue, we took immediate action to minimize impact, identify and halt affected instruments.
We have identified the weaknesses in our QA processes and raised the issue with the vendor. We would like to assure market participants that access to this particular feature has been disabled. We are confident that this or similar issues will not be allowed to happen again going forward.
As of 17:00 JST today (May 29) the trading halt on all twelve affected instruments has been lifted, and we have resumed normal operations.
Again, we extend our sincere apologies for this incident.