The Netherlands Authority for Consumers and Markets (ACM) has issued a reprimand to an international company involved in the wholesale natural gas market due to indications of market manipulation. This manipulation, referred to as 'marking the close', involves actions that can distort the reference price of natural gas, ultimately affecting energy prices for consumers and businesses.

The Dutch wholesale market for natural gas, known as TTF, is the largest in Europe, trading three times the volume of all other European natural gas markets combined. The prices determined on this platform significantly influence energy costs across the Netherlands and other European countries. ACM is committed to ensuring compliance with European regulations, particularly the REMIT regulation, which aims to prevent market manipulation and protect consumers.

'Marking the close' is a practice where a trader influences the reference price by executing trades just before the market closes. This can involve placing high asking prices or buying large volumes to artificially inflate the price, benefiting the trader at the expense of others in the market. Such practices can lead to increased costs for consumers and businesses alike.

In response to these issues, ACM is encouraging market participants to report any suspicious trading activities through ACER’s Notification Platform. The authority is also actively monitoring the market to prevent insider trading and ensure compliance with transparency regulations. ACM collaborates with other regulatory bodies, including the Dutch Authority for the Financial Markets and the EU Agency for the Cooperation of Energy Regulators, to uphold market integrity.