Bitcoin miner Marathon Digital Holdings (NASDAQ: MARA) produced 196 bitcoins in November, down from 417.7 in October, as maintenance and upgrades to its power generating stations in Hardin, Montana, cut computing power.

“While these upgrades caused our miners in Hardin to operate below capacity in November, which negatively impacted our bitcoin production for the month, we believe they were necessary in the near term and will be beneficial in the long run,” Marathon CEO Fred Thiel said in a statement Friday.

Marathon said after many of its plant issues were fixed, the Hardin fleet was operating near full capacity, allowing the company to produce 34 bitcoins on the first day of December. Shares of Marathon fell about 7.5% to roughly $45.39 Friday morning on the news.

The company boosted its total bitcoin holdings to about 7,649.1 with a fair market value of roughly $437.4 million, slightly down from last month’s figure of about $457.4 million.

Marathon’s fleet consists of 31,000 active miners producing approximately 3.2 exahashes per second (EH/s). The company received another 15,520 top-tier ASIC miners from Bitmain last month. So far this year it’s taken delivery of 56,826 miners, with another 8,477 on the way.

Read more: Marathon Digital Expands Compute North Hosting Deal to Over 100K Bitcoin Miners

UPDATE (Dec. 3, 15:18 UTC): Adds stock price movement.

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