Marathon Digital, the world’s largest Bitcoin mining firm, announced on Thursday that it has purchased $100 million worth of BTC for its balance sheet.

That brings the mining giant’s total Bitcoin holdings up to 20,000 BTC, worth $1.28 billion at present. Going forward, the company doesn’t plan to sell a single satoshi (aka the smallest unit of Bitcoin).

“Effective immediately, MARA will once again adopt a full HODL strategy,” Marathon said on Twitter. “The company plans to retain all Bitcoin mined and periodically make strategic purchases on the open market.”

MARA's share price is up less than 1% on the day to a current price of $20.83 as of this writing.

Marathon’s action mirrors those of several other public companies adopting Bitcoin as a primary treasury reserve asset this year, including Semler Scientific, Japan’s MetaPlanet, and Canada’s DeFi Technologies.

The stock price of all such companies surged immediately after they announced their respective new strategies—particularly MetaPlanet, which is up 1,200% year to date.

As a popular mining company, MARA has always traded in tandem with the broader Bitcoin market and held some amount of BTC in its coffers.

Yet many mining companies—such as IREN—prefer to liquidate their Bitcoin the moment it is mined, instead of “HODLing” their coins. Marathon has sold BTC regularly over the past year, but is now focused on preserving its coins due to what it sees as rising institutional adoption and a bullish macro environment.

According to a JPMorgan report earlier this month, Marathon mined more Bitcoin than any other mining company in June. However, the firm’s BTC per EH/s rate—a measure of the company’s ability to cost-effectively mine—was beat out by several competitors like IREN, CleanSpark, and Bitfarms.

Meanwhile, Bitcoin’s total hash rate has exploded and is now close to all-time highs. The latest jump could lead mining difficulty to jump 11% to its highest level ever within a few days, creating even tighter margins for mining businesses at large.

Marathon’s decision to buy Bitcoin may indicate that the firm sees more value in simply buying BTC in the short term than investing in mining infrastructure.

“We believe Bitcoin is the world’s best treasury reserve asset and support the idea of sovereign wealth funds holding it,” said Fred Thiel, MARA’s chairman and CEO. “We encourage governments and corporations to all hold Bitcoin as a reserve asset.”

Edited by Andrew Hayward