Under Fred Thiel's leadership, MARA Holdings (MARA) — previously known as Marathon Digital Holdings — has become not only one of the largest bitcoin miners in the world but also the second-largest corporate owner of bitcoin, with about $3.9 billion worth on its balance sheet. Thiel joined the mining company in 2018 as a director and was appointed CEO in 2021. Since then, he has navigated through the bull market of 2021 and the subsequent brutal crypto winter. His company has been focused on a bitcoin-centric business model, while other miners had to pivot to artificial intelligence-related computing as the industry faced reduced margins following the recent bitcoin halving event. Under Thiel, MARA went all-in on bitcoin by becoming the first miner to follow MicroStrategy executive chairman Michael Saylor’s lead and buy large amounts of the digital asset on the spot market. The company was even able to successfully raise $1 billion recently to buy more bitcoin, making Thiel perhaps the Michael Saylor of the bitcoin mining industry.