Outline of Transaction

JEPX offers two types of trading: A day-ahead trading called Spot/Intraday Market as the main market, and after-market trading called Forward Market as the adjustment market for bulletin board products.
Please refer to the following trading guide (in Japanese) for more information on trading on the JEPX including the aforementioned markets.

JEPX trading guidelines
(Language: Japanese; Revised on January 22, 2019)

Spot/Intraday Market (a day-ahead market)

This is the market where the electricity to be delivered the next day is traded. 48 products are traded every 30 minutes in a 24-hour period.

The bidding is done through a system called Blind Single Price Auction, where the price is traded at the contracted price regardless of the bid price. For example, if a bid is placed at ¥10/kWh, but the contract price is ¥15/kWh, it will be sold at ¥15/kWh. The “blind” refers to the fact that one cannot see the bids of other participants at the time of bidding.

Forward Market (bulletin board products)

On the following day, after electricity is traded in the Spot Market, unforeseen power generation problems or demand surges may occur during the period between the planned and actual delivery.
The Forward Market is designed to address such unforeseen supply-demand mismatches that occur after the next day's plan is formulated. The contract is executed as a continuous session.