Tether, the issuer of the USDT stablecoin, increased its holdings in bitcoin (BTC) miner Bitdeer (BTDR), building on a investment it started almost a year ago.

The company financed the acquisition with working capital and now owns 21% of the company, according to a Securities and Exchange Commission filing.

Tether first acquired a position in the Singapore-based company last May with a $100 million investment for 18.59 million Class A shares and an option to buy 5 million more at $10 each.

Tether is building a portfolio of holdings with its record profits, which came in at $13 billion last year, acquiring a stake in Italty’s Juventus FC and bidding for a majority stake in Latin American agricultural commodities producer Adecoagro.

Bitdeer’s stock is unchanged on Nasdaq pre-market trading, changing hands at $10.56.

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