Holders of BHP shares got an awkward surprise in the miner's fourth-quarter operational review.
The June quarter numbers themselves were fine, but it was the forward guidance that caused the trouble.
BHP Group Ltd (ASX: BHP) guided FY27 copper production to between 1,650 and 1,800 kilotonnes.
That represents a step-down of more than 150 kilotonnes on what the company produced in FY26.
As a result, BHP shares were sold off after the announcement.
Image source: Getty Images
What the guidance said
First, let's assess the quarter itself.
Iron ore production of 68.1 million tonnes came in close to the consensus estimate of 68.3 million tonnes.
Copper output of 491.9 kilotonnes edged past the 490.6 kilotonne forecast.
Finally, coal beat outright.
BHP delivered record iron ore production for the full year and produced roughly 2 million tonnes of copper for a second consecutive year.
So, the problem is not the past.
Looking ahead, the FY27 copper guide reflects lower ore grades and planned maintenance, both of which are ordinary features of mining rather than signs of fundamental issues with the business.
FY27 iron ore guidance was left broadly flat at 284 to 296 million tonnes and realised iron ore prices of US$83.6 per tonne were also in line with expectations.
We can therefore deduce that BHP is not facing a demand problem.
Recent earnings and why BHP shares re-rated
To understand why the copper number stung, you need the February result.
Copper contributed 51% of group EBITDA in the first half of FY26. As a result, copper became the future growth catalyst that has justified a higher multiple on BHP shares.
As a result, any downward revision on future copper growth and earnings, as we saw in the lates update, can cause investors to scale back the re-rating.
The offset supporting BHP shares
However, it was not all bad news for BHP shareholders.
For one, BHP was able to strengthen its balance sheet. Net debt fell to around $9 billion at the end of June, down from $14.7 billion at the end of December. That is a reduction of roughly 40% in six months.
Asset sales of $5.2 billion did most of the work, led by a US$4.3 billion silver streaming deal covering BHP's share of Antamina production.
Strong free cash flow handled the rest.
BHP operates a minimum 50% payout ratio on underlying attributable profit.
A lighter debt load heading into the FY26 result on 18 August gives the board more room and flexibility than it had six months ago.
Foolish takeaway
I would not read the copper guidance as a thesis-breaker for BHP shares.
Grades decline and maintenance gets scheduled, but one can argue that this is part of the mining cycle.
The more meaningful answers arrive on 18 August, when BHP reports unit costs, capital guidance and the final dividend.
Capital discipline a key variable to watch, particularly with the Vicuña project and Copper South Australia both progressing.
As a result, investors should remain patient before making any decisions based on the last trading update.
