Senator Elizabeth Warren has sent a letter to Commerce Secretary Howard Lutnick requesting documents and communications related to Bitmain, the Chinese company that manufactures a large share of the world’s Bitcoin mining equipment.

Operation Red Sunset

In November last year, US authorities launched an investigation into Bitmain dubbed “Operation Red Sunset,” led by the Department of Homeland Security.

The probe aimed to examine whether Bitmain’s ASIC machines could be remotely accessed for espionage or used to disrupt the US power grid.

According to Bloomberg, the investigation remains unresolved, and its current status is unclear — national security probes of this type can run for years without public disclosure or legal action.

Deepening scrutiny

The concerns are not new.

In 2024, a federal review flagged the use of Bitmain machines near a US military base as raising “significant national security concerns.”

Authorities also previously halted shipments of Bitmain devices and launched a separate investigation into a related Chinese chip firm over alleged links to sanctioned Huawei.

Despite the scrutiny, Bitmain was reportedly preparing to open its first US-based ASIC manufacturing facility, with chip production expected to begin in early 2026 and scale by year-end, according to Bloomberg.

Trump family ties raise questions

Bitmain’s machines are widely used across the industry, including by American Bitcoin Corp., which counts Eric Trump and Donald Trump Jr. among its investors.

The firm agreed last year to acquire 16,000 Bitmain rigs in a $314 million deal.

Warren’s letter also seeks details on any communications between Bitmain, the Trump family, and Commerce officials, and asks what steps the department has taken to shield national security decisions from political influence.

Neither Warren’s office nor Bitmain had responded to requests for comment by the time of publication.