Publication date: Sept 24, 2025
What Market Participants Can Expect From JEPX’s New Trading System
What market participants can expect from JEPX’s new trading system The Japan Electric Power eXchange (JEPX) plans to revamp its trading systems in 2026, with the day-ahead (spot) market system set for renewal in February, followed by the intraday market system in April. Under the new framework, the current graphical user interface (GUI) for trading will be phased out, shifting entirely to server-to-server data transmission between market participants and JEPX. Participants will need to either establish a dedicated line and develop their own trading functions or contract third-party providers offering similar services.
Key changes under the new systems:
- User registration will be discontinued (per-user operations will be eliminated).
- Spot market: transition from block bidding to single bidding.
- Each bid will be assigned a delivery code.
- A user-defined text entry field will be added, allowing users to distinguish their bids.
What Market Participants Can Expect From JEPX’s New Trading System
System Migration Timeline and Fee Revisions
The current spot market trading system will run in parallel with the new system even after February 2026, with the duration depending on participant readiness. The test environment for the new spot market system will be available in October 2025. Meanwhile, the intraday market trading system will fully migrate to the new system in April 2026 without parallel operation, with its test environment opening in December 2025.
Along with the system renewal, a revision of fees is also planned for April 2026. The annual membership fee will significantly increase from the current JPY 360,000 to JPY 2,000,000, while the spot market transaction fee will be reduced from JPY 30 per MWh to JPY 1 per MWh (with the flat-rate scheme abolished). The intraday market transaction fee will be reduced from JPY 100 per MWh to JPY 5 per MWh. In addition, the usage fee for the existing spot market system will be JPY 300,000 per month. What Market Participants Can Expect From JEPX’s New Trading System
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