Why are Northern Star shares crashing 10% today?

Northern Star Resources Ltd (ASX: NST) shares are starting the year in a disappointing fashion.

In morning trade, the gold miner’s shares are down 10% to $23.99.

Why are Northern Star shares crashing?

The catalyst for today’s selloff has been the release of an operational update this morning.

According to the release, Northern Star’s December quarter gold sales were impacted by a number of isolated negative events coinciding at its operations late in the quarter.

Total sales were ~348,000 ounces during the three months, resulting in first half FY 2026 gold sales of ~729,000 ounces.

This was well short of expectations. As a result of this softer operational performance, the company has revised its annual production guidance to between 1.6 million ounces and 1.7 million ounces, from between 1.7 million ounces and 1.85 million ounces.

Management also revealed that its lower gold sales are expected to impact its cost performance. However, it will provide its December quarter costs and revised annual cost guidance with its quarterly results release later this month.

What happened to its production?

In addition to previously disclosed events at its Jundee and South Kalgoorlie operations, which collectively impacted production by up to 20,000 ounces, management notes that the quarter was further affected by several unplanned maintenance and operational challenges.

For the Kalgoorlie Production Centre, December gold sales totalled ~203,000 ounces. At KCGM, gold sold was ~110,000 ounces driven by reduced throughput in the processing plant because of the primary crusher failure, which has impacted production for four weeks. Milled grades achieved were ~1.6g/t, higher than the September quarter.

While the processing plant will return to normal operations in early January, throughput is expected to remain variable during the second half as it transitions from the existing plant to the new expanded mill. It is on track for commissioning in early FY 2027.

For the Yandal Production Centre, December gold sales were ~91,000 ounces. This reflects weaker performances at both Jundee and Thunderbox.

At Jundee, recovery works have taken longer than planned, with a return to normal operations now expected during the March quarter. At Thunderbox, gold sales were impacted by continued lower mined grades from the Orelia open pit and unplanned processing downtime associated with carbon-in-leach tank failures.

Finally, at Pogo, gold sales of ~53,000 ounces were affected by lower mined grades due to underground mining dilution. The Pogo underground mine and mill operated at an annualised run rate of 1.4Mtpa during the December quarter.

The post Why are Northern Star shares crashing 10% today? appeared first on The Motley Fool Australia.

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Motley Fool contributor James Mickleboro has no position in any of the stocks mentioned. The Motley Fool Australia’s parent company Motley Fool Holdings Inc. has no position in any of the stocks mentioned. The Motley Fool Australia has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.