GOP Lawmaker Seeks Reviews of Two Bitcoin Mining Machine Makers

Chinese firms say they operate in compliance with US laws

Antminer hash boards, a product of the Bitcoin mining equipment maker Bitmain Technologies Ltd., were photographed in July 2021.

Photographer: Andrey Rudakov/Bloomberg

A Republican lawmaker has called for a federal review of two companies that manufacture Bitcoin mining hardware, saying that their increasing presence in the US could present a national security risk, according to a letter reviewed by Bloomberg News.

One of the companies is Bitmain Technologies Ltd., a China-based firm that is the world’s leading manufacturer of cryptocurrency mining machines. The other, Cango Inc., is a potential acquisition target for Bitmain, Representative Zachary Nunn of Iowa wrote.