According to Foresight News, Riot Blockchain has announced a $290.5 million purchase of new generation MicroBT Bitcoin mining machines. The new order will primarily include the recently released M66S model from MicroBT, with an efficiency rating of 18.5 EH/s. All mining machines in the order will be manufactured in the United States and specifically designed for immersion cooling. Riot CEO Jason Les stated that this order is the largest computing power order in the company's history.