US Congressman Demands Review of Bitmain and Cango

US Congressman Zachary Nunn urged the Treasury to investigate Bitmain and Cango over national security concerns, citing foreign ties and growing presence in Bitcoin mining.

National security concerns over Bitcoin mining

Republican lawmaker Zachary Nunn has called on the US Treasury Department to review the activities of Bitmain and Cango. He warned that the firms may pose national security risks.

According to Bloomberg, Nunn sent a Sept. 2 letter to Treasury Secretary Scott Bessent, asking the Committee on Foreign Investment in the United States (CFIUS) to launch a probe. His concerns stem from the rapid expansion of Chinese-linked players in the American crypto mining market.

Nunn argued that Bitmain and Cango appear to be scaling operations through complex financing structures that lack transparency for regulators.

Cango’s pivot and Bitmain’s influence

Cango, once a Chinese auto services firm, has pivoted into Bitcoin mining and emerged as one of the top five global players. In August, it mined 664 BTC, surpassing CleanSpark and becoming the third-largest miner after MARA and IREN by realized hashrate.

Both Bitmain and Cango denied merger rumors, stating that they comply with US laws and are not tied to the Chinese government. However, Cango’s expansion was largely financed by Antalpha, Bitmain’s financial arm, making it a key proxy.

Policy implications and risks

Nunn’s letter highlighted risks including Cango’s alleged ties to foreign state actors, Bitmain’s rumored interest in US power assets, and the broader implications of using foreign-made mining chips domestically.

Meanwhile, Bitmain remains a backbone of the global mining sector. American Bitcoin Corp., a newly listed company backed by Donald Trump Jr. and Eric Trump, recently purchased over $300 million worth of rigs from the manufacturer.