Highlights

  • FY26 operating cost guidance rises to AUD 2,600–2,800/oz after softer December quarter sales.
  • Production guidance reduced to 1,600–1,700koz due to operational challenges across all centres.
  • December quarter operational issues have directly influenced cost and annual production expectations.
  • NST shares rose 1.05% as on 20 January 2026 despite reduced guidance.

Northern Star Resources Ltd (ASX:NST) provided an update on its FY26 all-in sustaining cost (AISC) guidance on 20 January 2026, following its operational update released on 2 January 2026. The company now expects FY26 AISC of AUD 2,600–2,800/oz, up from the previous range of AUD 2,300–2,700/oz, primarily driven by lower gold sales and higher royalties from elevated gold prices, adding roughly AUD 40/oz compared to the initial forecast

Sustaining capital guidance remains at AUD 750 million, equivalent to approximately AUD 450/oz, slightly above the previous AUD 420/oz estimate. First-half FY26 AISC averaged AUD 2,720/oz, following 2,522/oz in 1Q and 2,937/oz in 2Q, reflecting the impact of production disruptions on overall cost performance.

Operational Challenges Shape FY26 Cost and Production Outlook

The 2 January 2026 operational update highlighted a softer December quarter, with total gold sales of 348koz, bringing first-half FY26 sales to 729koz. All three production centres — Kalgoorlie, Yandal, and Pogo, experienced challenges that contributed to lower output and higher costs:

Kalgoorlie: 203koz sold; KCGM impacted by primary crusher failure, causing reduced throughput for four weeks. Mining and milling continued toward annual targets, with Golden Pike North ore stockpiled for processing in second half of FY26.

Yandal (Jundee and Thunderbox): 91koz sold; delays in structural repairs and lower mined grades affected output. Cost-focused measures such as reducing the mining fleet were implemented.

Pogo: 53koz sold; underground mining dilution lowered grades, with milling operating at an annualized 1.4Mtpa.

Collectively, these events prompted the revision of FY26 production guidance to 1,600–1,700koz, down from the previous 1,700–1,850koz, and increased expected costs.

Market Response Despite Challenges

However, even though Northern Star Resources has revised down its FY26 production guidance and raised all-in sustaining cost expectations, NST shares have shown upward movement in recent trading sessions. At the time of writing, the NSTshares have jumped by 1.05% to AUD 27.97 and has also delivered a one-year returns of 64.63% as on 20 January 2026. This response reflects broader market dynamics, including gold price trends and investor positioning, rather than changes in the company’s underlying operational performance. Since the December quarter disruptions are now factored into guidance, the market appears to be adjusting trading activity based on updated operational and cost information, even as the revised guidance highlights the challenges faced across the company’s production centres.