Bitcoin has been plummeting for several weeks now and other cryptos are following the same slippery slope toward the abyss. Together, they take investors, both small and big, often helpless in the face of violent shocks. Even the industry giants sneeze in this difficult context. Miners, these blacksmiths who keep the blockchain running day and night, take particularly painful hits. Extracting bitcoins hardly yields anything today. Worse, this activity now costs more than it brings in.