CleanSpark Most Shorted U.S. Bitcoin Miner

CleanSpark (Nasdaq: CLSK) has the largest share of short interest among U.S. Bitcoin miners, with 34.89% of its free float sold short and 4.71 days to cover, according to market data. MicroStrategy holds a larger dollar value of shorted shares, while CleanSpark leads on a percentage-of-float basis. CLSK shares traded at $11.42, up from $8.18 at the end of March.

The company provides shared Bitcoin-mining services and reports up to 50 exahashes per second of capacity. CleanSpark reported $766.3 million in revenue and $364.5 million in net income for 2025, and it ended the year with about $1 billion in working capital. The operator held 13,363 BTC from mining and legacy operations at year end.

Investors and market participants cite several factors behind the heavy short interest. Mining revenue and cash flow are sensitive to Bitcoin price swings and periods of unprofitable mining. CleanSpark increased outstanding common shares from about 22 million in 2020 to roughly 280 million today. The company announced a buyback program for 40 million shares.

Company disclosures show CleanSpark announced plans to enter AI data-center work in late 2025. The filings do not list signed contracts for an AI data-center business.

Market participants compare CleanSpark with other firms that operate mining facilities or hold Bitcoin treasuries, including Marathon Digital and IREN. Some analysts say concentrated short positions can lead to rapid price moves if buying pressure increases.

The company’s 2025 profitability from mining operations is recorded in its financials. Market participants also point to potential risks such as mining-asset depreciation and the decommissioning of older equipment as factors affecting future results.