Tokyo Stock Exchange upgrades its “arrowhead” trading system
Newly introduced features prevent sudden fluctuations in stock prices, improve the opportunity to conclude contracts based on closing prices, and stabilize system performance.

Tokyo Stock Exchange, Inc. (TSE) and Fujitsu Limited today announce an important upgrade to TSE’s “arrowhead” trading system. The overhauled system begins operating today.
Newly introduced features prevent sudden fluctuations in stock prices, improve the opportunity to conclude contracts based on closing prices, and stabilize system performance.
The new version of “arrowhead” uses the existing system as a base for an upgraded technology that offers users the familiar, high speed, high reliability experience, while delivering even greater convenience. The trading system and transaction services have been improved in order to respond to changes in the business environment and better meet the needs of users, providing stronger overall market functionality.
For closing (the final trades at the end of the day), this version doubles the renewal price interval. This will make it easier to execute trades at closing, when trading needs are quite high.
TSE has deployed a system called sequential trade quotes, as part of an effort to improve control over sudden and sharp changes in price. Now, the system is being further improved to prevent excessive price fluctuations beyond a certain price range (double the update price range of the Special Quotes) until a certain amount of time (60 seconds) has passed from the reference execution.
The system’s processing capability is being improved to process trades in a stable way even when orders from participants are concentrated at certain times or when the number of orders suddenly increases. In particular, the new “arrowhead” will provide a stable environment for transactions by limiting the degree of instability in processing performance when orders are concentrated.
In order to increase opportunities for developers of trading systems that connect users with “arrowhead” to check the functionality of their products in TSE’s test environment, TSE will now be providing an environment where developers can run tests from early morning to late night on all working days, where tests previously had to be conducted on specific days. This will contribute to greater safety and improved convenience for the market as a whole.
The overhaul of “arrowhead” is improving both reliability and processing performance, combining the latest products, including Fujitsu’s high reliability, high performance servers and middleware incorporating new technology to improve speed and reliability, with the full strength of the know-how and technical abilities of Fujitsu’s engineers, built up over many years of system building.
The new “arrowhead” consists of 400 Fujitsu Server PRIMERGY RX2540 M4 servers, Fujitsu’s latest high performance, high reliability x86 server. The technology enables nanosecond-level ultra-high-speed data access by storing all data necessary for processing in memory, providing high response and throughput performance. In addition, for data stored in memory, data integrity is ensured through constant mirroring to triply-redundant standby servers, enabling the system to switch servers in seconds when there is a fault.
This update also delivers new functions that increase processing efficiency, such as a batch processing function.