CleanSpark reports 529 bitcoin mined in September as daily output falls

A bitcoin miner's September report pairs lower daily output with a smaller treasury as monthly operating updates come to an end. CleanSpark, Inc. NASDAQCLSK, the U.S. bitcoin miner and data centre developer, reported on Oct. 9 that it produced 529 bitcoin in September, down from 593 in August.

CleanSpark shares closed at US$10.63 on Nasdaq at 4 p.m. EDT on Oct. 8, before the operating report, according to the NASDAQCLSK quote page. That closing quote does not measure a market response to the Oct. 9 figures.

The company's average operating hashrate slipped to 36.0 exahashes per second in September from 38.3 in its August operating report. Daily production averaged 17.64 bitcoin, down from 19.12 in August. Extended over a year, September's daily rate would yield about 6,440 bitcoin, an arithmetic comparison rather than company guidance.

September's unaudited update also put bitcoin holdings at 13,530 on Sept. 30, down from 13,703 on Aug. 31. CleanSpark said it will stop monthly operational updates and move to quarterly reporting, removing the regular monthly view of how output tracks against installed capacity.

Reported 50 EH/s Hashrate Marks a Historical High

CleanSpark reported an operational hashrate of 50 exahashes per second in both its September and August updates. The Oct. 9 release defines that metric as the highest hashrate historically achieved concurrently by installed, energized and functional miners. It does not identify a September peak; September's average operating hashrate was 36.0 exahashes per second.

CleanSpark deployed 199,745 miners as of Sept. 30, down from 201,269 on Aug. 31. Peak efficiency was unchanged at 16.07 joules per terahash in the two monthly operating tables. The release does not assign a cause to the lower average rate, so the lower output cannot be attributed to a specific outage or network change from these figures alone.

CleanSpark also listed 1.8 gigawatts of contracted power and 808 megawatts of maximum concurrent power use in support of the fleet's operational hashrate, both unchanged from August. Its contracted-power figure covers wholly owned and leased sites, while utilized megawatts measure a peak for energized mining equipment. Their difference is not a measure of immediately available mining capacity or a schedule for converting sites to AI hosting.

The company reported 5,432 bitcoin produced during calendar 2026 through Sept. 30. That cumulative figure includes the weaker September month; the 529 bitcoin mined in September was about 11 per cent below August's 593. The fall in average daily production was smaller, about eight per cent, because September had one fewer day than August.

Call Exercises Reduced the Bitcoin Treasury

CleanSpark's September treasury table shows 700 bitcoin sold pursuant to call exercises and two sold at spot. Adding the month's 529 produced bitcoin to Aug. 31 holdings, then subtracting those sales, reconciles to the 13,530 bitcoin reported for Sept. 30. The balance fell by 173 bitcoin despite fresh mining output.

Of the Sept. 30 balance, 3,475 bitcoin was posted as collateral or recorded as receivable in connection with derivatives transactions, according to the Sept. 30 table. These categories sit inside reported holdings; the headline treasury number alone does not show how much bitcoin was free of those arrangements at month-end.

The Sept. 30 table gives an average price of US$72,928 per bitcoin sold, compared with US$65,420 in August. CleanSpark calculates that average from net sale proceeds plus net premiums generated, divided by bitcoin sold, so it is not simply a September spot-market execution price. The Sept. 30 treasury table gives no separate proceeds figure for the two spot sales.

Sandersville Financing Is Closed, While Construction Continues

CleanSpark's subsidiary CSDC Finance I closed US$2.276 billion of senior secured notes on Sept. 25. The notes carry a 7.875 per cent coupon and mature in 2031. In the Oct. 9 operating release, CleanSpark says the financing funds its Sandersville data centre build-out for a lease it expects to generate about US$6.6 billion of contracted revenue over its initial term.

"With non-dilutive bond financing now in place, our Sandersville project is fully funded through completion," CleanSpark chief executive and chairman Matt Schultz said in the Oct. 9 release.

That statement concerns expected project funding, while September's mining table measures an operating fleet. CleanSpark's August release had already described Sandersville construction as ongoing; the October update gives no construction completion date. The projected lease revenue is a future estimate, separate from September's mined bitcoin count.

Bitdeer Technologies Group NASDAQBTDR, a Singapore-based bitcoin miner and AI infrastructure operator, reported 1,310 bitcoin mined in August, alongside a 79.9-exahash-per-second self-mining rate. It held 61 bitcoin at Aug. 31. Bitdeer's self-mining rate and CleanSpark's historical operational high use different definitions, while their treasury balances show different month-end exposure to the asset.

The commercial shift from mining toward customer compute capacity has also appeared in Mugglehead's recent AI hosting earnings coverage. For CleanSpark, the September report still shows bitcoin mining as the activity generating its monthly production figures; the lease projection concerns Sandersville construction, while the 529-bitcoin figure comes from the mining fleet.

Read more: Applied Digital Corporation reports US$341.9M revenue, US$221M loss

The current calendar quarter ends Dec. 31, 2026, the next quarter-end date after the September report. CleanSpark's Oct. 9 release says it will replace monthly operational updates with quarterly ones but gives neither a date for the first update nor a list of metrics it will contain.