BHP sinks 3% as Jansen potash costs blow out by $5 billion

BHP Group Ltd shares fell 3% Tuesday after the miner disclosed a $5 billion cost overrun on the Jansen stage 2 potash project in Saskatchewan, pushing total capital expenditure for the two-phase development past $20 billion.

The revised budget, disclosed in a regulatory filing, puts stage 2 at roughly $12 billion, up from the $7 billion estimate BHP gave when it approved the project in 2023. Stage 1, already under construction, carries a $7.5 billion price tag. Combined, the two phases now exceed the $10–12 billion range BHP had signaled as recently as last year.

BHP said the increase reflects higher labour costs, supply-chain delays, and design changes to the underground mining infrastructure. The company did not revise its timeline – first production from stage 1 remains on track for late 2026, with stage 2 following in 2028.

Potash is central to BHP's strategy of diversifying beyond iron ore and copper. The Jansen project, when fully built, would make BHP one of the top five global potash producers, with capacity of roughly 16 million tonnes a year. The cost blowup raises questions about the project's return profile at current potash prices, which have fallen about 30% from their 2022 peaks after Russia and Belarus restored export volumes.

Analysts at Macquarie cut their price target on BHP by 4% following the announcement, citing higher capital intensity and a longer payback period. The stock closed at A$42.15, its lowest in three weeks.

BHP's Alpha Score sits at 73 out of 100, a Moderate rating, reflecting the tension between its strong free-cash-flow generation from iron ore and the rising execution risk in potash. The Jansen cost overrun is the second major capital surprise from BHP this year – the miner also flagged higher spending at its Escondida copper mine in Chile during its half-year results.

For investors tracking the potash thesis, the next concrete marker is the stage 1 commissioning update, due in BHP's September-quarter operational review. A further cost revision before then would pressure the stock toward the A$40 support level that has held since November.