10 Best Mid Cap Stocks to Invest In According to Billionaires

8. CleanSpark, Inc. (NASDAQ:CLSK)

Number of Billionaire Holdings: 10

Market Cap: $2.61 billion

CleanSpark, Inc. (NASDAQ:CLSK) is one of the best mid cap stock on this list.

TheFly reported on April 9 that Cantor Fitzgerald reiterated its Overweight rating on CLSK while cutting its price target from $17 to $14. The firm highlighted growing demand for AI infrastructure as adoption expands across industries, viewing the space as a strong investment opportunity regardless of which technologies lead the market. It also expects a continued imbalance between supply and demand over the coming years, which could support sustained pricing strength.

Additionally, CleanSpark, Inc. (NASDAQ:CLSK) published its March 2026 operational update on April 7, reporting total Bitcoin production of 658 for the month, with an average daily output of 21.24. Year-to-date production reached 1,799 Bitcoin. The company achieved an operational hashrate of 50.0 EH/s, while maintaining an average running hashrate of 47.3 EH/s during the period.

Its contracted power capacity stood at 1.8 gigawatts. CLSK’s total Bitcoin holdings increased from 13,363 at the end of February to 13,561 by March 31. Additionally, the average selling price for Bitcoin during the month was reported at $71,396, reflecting continued operational consistency and expansion in mining capacity.

CleanSpark, Inc. (NASDAQ:CLSK) is a sustainable bitcoin mining company focused on energy-efficient operations. It develops and operates data centers powered by low-carbon energy, while also offering energy technology solutions to optimize power usage and enhance grid resilience.