What a $120M Mining Bust Reveals About Tether’s Hidden Portfolio

Points of Focus

• Tether spent roughly $120M on two Uruguay mining sites, both now abandoned.
• The bet sits inside a $20B portfolio of over 100 largely undisclosed investments.
• The write-off illustrates the exact reserve categories GENIUS Act rules target.

A Reuters investigation published Aug. 21, and based on internal utility documents and interviews with former contractors, confirmed that Tether spent roughly $120 million building two bitcoin mining sites in Uruguay’s Florida department in 2023, then abandoned both after a contract dispute over electricity supply with state utility UTE.

⚡️JUST IN: Tether’s $120 MILLION BTC mining bet in Uruguay has GONE DARK.

A dispute over unpaid power bills and a revised electricity contract led state-owned utility UTE to cut electricity to the sites in July 2025, per Reuters.

The shutdown derailed a project meant to anchor… pic.twitter.com/v2Fv8Dg29x

— Coin Bureau (@coinbureau) August 23, 2026

Tether did not respond to Reuters’ requests for comment.

Uruguay bet collapsed over a power supply dispute

The dispute began by Nov. 2024, according to an internal UTE briefing Reuters reviewed. Tether read a clause in its power contract as a minimum supply level that could be increased on request. UTE read the same clause as a hard maximum. 

As demand at the sites rose, Tether ran short of electricity for days at a time, a former contractor stated. A change in Uruguay’s government in March 2025 brought in new UTE directors who took a harder line on renegotiation. 

Tether’s local entity, Microfin, stopped paying its power bills two months later and told UTE in June 2025 it would terminate the contracts. UTE cut power to the sites on July 25, 2025, and Tether notified Uruguay’s labor authorities that, in November it would lay off most staff. Microfin settled its outstanding bills in December.

Crypto mining expert Nicolas Ribeiro, quoted in the Reuters piece, put it plainly: Uruguay’s power costs are too high for mining economics to work, whatever the grid’s other strengths. 

Assistant professor Pete Howson described the underlying pattern as bitcoin mining’s hypermobile nature, infrastructure that can be unplugged and moved elsewhere with little lasting benefit to the host country.

A $120M write-off inside a largely undisclosed portfolio

The more useful detail isn’t the mining failure itself. It’s where that $120 million sits. Tether controls roughly $183 billion in stablecoins in circulation. From its Treasury holdings and profits, it has built an investment portfolio it values at around $20 billion, spanning more than 100 positions the company mostly does not disclose. The Uruguay bet only became visible because outside reporters dug through utility records and found former employees willing to talk.

That opacity is not incidental to GENIUS Act reserve rules, which exist specifically to constrain the kind of speculative, illiquid asset exposure a quietly abandoned mining bet represents. 

As of Tether’s BDO-assured reserve breakdown for Jun. 30, roughly 25% of total assets fall outside GENIUS Act-permitted reserve categories once precious metals, bitcoin, secured loans, and “Other Investments” are counted together. A $120 million write-off nobody heard about until Reuters found it is a concrete, dollar-denominated example of exactly that risk category, not an abstract compliance concern.

What comes next for Tether’s disclosure practices

Tether has since announced mining investments in Brazil, following what a former contractor described to Reuters as an intended pattern, testing Uruguay before larger South American markets. 

Whether Brazil repeats Uruguay’s outcome is an open question worth tracking rather than assuming either way. What’s already established is that a single Reuters investigation surfaced more concrete detail about Tether’s investment failures than the company’s disclosures have offered in nearly three years since the Uruguay project began.