Publicly traded Bitcoin (BTC) mining firms reached a market cap of well over $43 billion. At the time of writing the cumulative market cap of those companies stands at $43.12 billion, according to Farside Investors data. The value of the considered firms more than doubled in seven months as Bitcoin’s price kept rallying. The details The biggest challenge for Bitcoin mining firms is revenue, especially considering that the Bitcoin block reward was cut by 50% in April.