BITMAIN, CONTROLLING 80% OF ASIC MARKET, FACES U.S. PROBE OVER NATIONAL SECURITY RISKS U.S. officials have opened a national security investigation into Bitmain, the company that dominates roughly 80% of the global ASIC mining hardware market. The probe centers on supply-chain dependence, hardware backdoors, and the strategic risk of a single foreign manufacturer controlling the core infrastructure that secures the Bitcoin network.