MARA Holdings Inc. – a US-based cryptocurrency mining firm – increased its Bitcoin (BTC) reserves by 373 BTC in September, pushing its total holdings to 52,850 from 52,477 BTC. Following today’s update, MARA remains the second-largest public company with BTC reserves, trailing Michael Saylor’s Strategy. MARA Holdings Increases Bitcoin Reserves According to an official announcement earlier today, MARA Holdings’ BTC reserves rose by 373 coins in September. The firm’s total BTC holdings are valued at approximately $6.4 billion, according to prevailing market prices. Notably, MARA Holdings mined a total of 736 BTC in September, valued at approximately $88.6 million. In comparison, the company had mined 704 BTC in August 2025, representing a 4.4% increase over the previous month. MARA Holdings’ amount of BTC mined in September represents roughly 5.2% of all miner rewards. This includes the transaction fees generated during the month. Unsurprisingly, MARA Holdings continues to be the largest public BTC miner in terms of BTC held. That said, it is worth highlighting that MARA Holdings’ Bitcoin stack consists of BTC that is loaned, actively managed, or used as collateral. Fred Thiel, Chairman and CEO, MARA Holdings, noted: In September, we produced 218 blocks, a 5% increase over August, demonstrating the continued strength and resilience of our operations even as global hashrate grew 9% month-over-month to an average of 1,031 EH/s. This growth in production underscores our ability to execute consistently, even as mining becomes more difficult. As mentioned earlier, MARA Holdings follows Strategy, the leading public company with the largest stack of BTC on its balance sheet. Strategy continued to increase its BTC stack, purchasing another $22 million worth of BTC earlier this week, propelling its total holdings to a mammoth 640,031 BTC, worth around $77 billion. Other public firms that feature among the top BTC holders include the likes of Twenty One (43,514 BTC), Japan-based Metaplanet (30,823 BTC), and Bitcoin Standard Treasury Company (30,021 BTC). In addition, well-known firms like Trump Media & Technology Group Corp., Galaxy Digital Holdings, Coinbase Global, Tesla, and Jack Dorsey-backed Block rank among the top 15 public companies with the largest BTC reserves. Companies Preferring Altcoins For Corporate Treasury While Bitcoin still reigns supreme in terms of being the most influential cryptocurrency with the highest adoption, altcoins such as Ethereum (ETH), Solana (SOL), and Avalanche (AVAX) are emerging as viable competition to BTC. For instance, NASDAQ-listed VisionSys AI recently announced that it plans to launch a Solana-based treasury program, valued at up to $2 billion. Similarly, a newly-created Avalanche-based treasury firm is expected to buy $1 billion worth of AVAX tokens in 2026. Meanwhile, Ethereum treasury firm BitMine bought 46,225 ETH in September, increasing its total ETH stack to more than 2.1 million ETH. At press time, BTC trades at $121,791, up 1.7% in the past 24 hours.
