6. Riot Platforms

Another crypto mining outfit, U.S.-based Riot Platforms, holds 15,680 BTC—worth nearly $1.2 billion at today’s prices. 

With its valuation surging from below $200 million in 2020 to highs of over $6 billion in 2021, the Nasdaq-listed company went on an aggressive expansion drive. In April 2021, it spent $650 million on a one-gigawatt Bitcoin mining facility in Texas, eventually expanding further in 2022 before rebranding to Riot Platforms to diversify its business model in 2023.