Bitcoin mining stocks opened sharply lower Tuesday to begin the trading week as bitcoin’s price retreated toward a critical support level. Major operators including MARA (NASDAQ: MARA) and Riot (NASDAQ: RIOT) erased recent gains and tracked a broader decline in cryptocurrency markets. Bitcoin traded at $90,489 on the stock market open, a loss of 2.28$90,000 mark and exerted downward pressure on bitcoin mining stock valuations across the board. MARA led the ...