Citi Research analyst Jim Suva on Tuesday has resumed coverage of eco-friendly cryptocurrency miner Iris Energy (NASDAQ:IREN) with a Buy/High Risk rating due to the slump in bitcoin (BTC-USD).Suva noted that his rating was similar to his restriction that was implemented in March, when bitcoin (BTC-USD) was trading at $44K. But bitcoin is off over 50% since then, changing hands at $21.45K as of shortly before 10:00 a.m. ET."The swings in the market value of its Bitcoin output directly impacts the revenues, earnings, and stock price," Suva wrote in a note to clients.In addition to bitcoin's (BTC-USD) drop, electricity and building costs, for instance, are rising amid multi-decade high inflation. That adds pressure to the company's bottom line results.The Buy rating diverges from the average Wall Street Analysts' Strong Buy rating (4 Strong Buy, 1 Hold).Previously, (August 9) Iris Energy mines 4.1% more bitcoins in July than prior month.