Billionaire Peter Thiel has bought a 9.1% stake in the crypto mining service company BitMine, which sent the company’s stock soaring in after-hour trading.

Shares in crypto mining service provider BitMine Immersion Technologies rallied 12.5% after the bell on Tuesday as billionaire venture capitalist Peter Thiel scooped up an over 9% stake in the firm.

Thiel bought 5.09 million shares in BitMine through various arms of his venture capital firm Founders Fund amounting to a 9.1% stake, according to a regulatory filing on Tuesday.

Thiel is best known for co-founding payments giant PayPal and software firm and defence contractor Palantir Technologies. His estimated net worth stands at $22.7 billion, making him the 92nd richest person in the world, according to Forbes.

Earlier this month Thiel and other tech billionaires filed for a bank charter to launch a new financial institution called Erebor, which aims to fill the void created by the collapse of the crypto-friendly Silicon Valley Bank in 2023.

In June, Thiel’s Founders Fund was reportedly leading a $200 million funding round in prediction market platform Polymarket, at a $1 billion valuation.qThiel-backed Bullish, a digital asset exchange, has reportedly filed confidential paperwork to go public via an initial public offering.