A Republican lawmaker is advocating for a national security review by the U.S. Treasury regarding two China-linked companies that are significant players in the Bitcoin mining hardware market. Representative Zachary Nunn from Iowa has raised alarms about the growing footprint of Bitmain and Cango in the United States, emphasizing concerns surrounding their ownership structures and potential ties to foreign state actors.
In a letter dated September 2, Nunn urged Treasury Secretary Scott Bessent to launch an inquiry into these companies, particularly highlighting the opaque ownership frameworks that may inhibit transparency to regulators and the public. Nunn, who is a member of the House Select Committee on the Chinese Communist Party, is focused on assessing Beijing’s influence across critical sectors, including emerging technologies like cryptocurrency.
Bitmain, based in Beijing, is recognized as the leading supplier of Bitcoin mining machines globally, holding over 80% of the market share according to a report from the University of Cambridge. Cango, which is publicly listed on Nasdaq, has recently been associated with Bitmain as a potential acquisition target, although Bitmain has officially refuted these claims.
Nunn’s request for a review is directed to the Committee on Foreign Investment in the United States (CFIUS), a body known for its involvement in high-profile investigations such as the scrutiny of TikTok and the aborted acquisition of Grindr. The previous year, a CFIUS review led to President Biden preventing a crypto mining facility from being established near a strategic U.S. Air Force base due to surveillance concerns.
This call for investigation comes shortly after American Bitcoin Corp, a mining firm supported by Eric Trump, acquired over $300 million worth of mining machines from Bitmain’s U.S. subsidiary. In the wake of this transaction, Bitmain clarified its position, denying any intent to gain ownership over U.S. energy infrastructures, countering speculation that it may be seeking to expand its operations into energy markets.
In the context of energy usage and potential affiliations with foreign governments, Nunn articulated his concerns over surveillance risks related to foreign-made chips. Both Bitmain and Cango have publicly asserted their compliance with U.S. laws and have denied any connections to governmental entities. Despite their denials of a possible merger, Nunn remains steadfast in his assertion that a review is essential to safeguard “American energy, digital asset markets, and financial sovereignty.”
The influence of Chinese entities over global Bitcoin mining remains significant, despite a ban on mining operations in China in 2021. Reports indicate that between 55% to 65% of Bitcoin mining is still connected to Chinese capital, hardware, or expertise. Major manufacturers like Bitmain, Canaan, and MicroBT, which collectively account for 99% of Bitcoin mining hardware production, have relocated to the U.S. to circumvent tariffs. This shift has resulted in an increase in America’s share of Bitcoin’s total hashrate from 4% in 2019 to a remarkable 38% today.
Former Chinese miners that have moved abroad often expand their operations significantly, with some reporting increases of up to 150%. While many Chinese mining activities have migrated overseas, limited mining still persists in certain remote areas of China where enforcement against these operations is less stringent.
