Shares of Mineral Resources Ltd (ASX:MIN) plummeted 5.05% in intraday trading following the company's announcement of a significant downgrade to its annual guidance for the Onslow Iron operation in Western Australia. The revision has sparked concerns among investors about the company's production capabilities and near-term outlook.

According to a late Tuesday announcement, Mineral Resources has lowered its volume guidance for Onslow Iron to between 7.8 million and 8.0 million metric tons for the fiscal year ending June, down from the previous forecast of 8.5 million to 8.7 million tons. The company cited lower-than-expected availability of contractor road trains to haul iron ore and below-forecast daily cycles as the primary reasons for the adjustment.

Despite the setback, Mineral Resources remains optimistic about its future performance. The company reported shipping 1.7 million tons of iron ore from the operation so far in May, with expectations to reach 1.9 million tons for the full month. Looking ahead to June, Mineral Resources projects shipments to range between 2.3 million and 2.6 million tons. Furthermore, the company affirmed that Onslow Iron is still on track to achieve its 35 million tonnes per annum capacity by the first quarter of fiscal year 2026, providing a silver lining for long-term investors amidst the current stock price decline.