Crypto miner MARA slips after June bitcoin production falls
** Bitcoin miner MARA Holdings' shares fall 2.6% to $15.27 premarket** Co says it produced 713 bitcoin in June, down from 950 in March ** Avg BTC produced per day declined to 23.8 in June vs 30.7 in prior month ** "The decrease was primarily due to reduced uptime from weather-related curtailment an…