The Australian Securities Exchange (ASX) has pressed Greatland Resources for answers on how it so significantly missed the production and cost targets set out in its prospectus, after the gold miner sharply downgraded output guidance and revealed a major capital expenditure jump.

In a response to an ASX “aware” letter, Greatland on Friday acknowledged that a reasonable person “would expect the updated production target to have a material effect on the price or value of its securities”.

The company last month cut its 2026 financial year gold production target to between 260 000 oz and 310 000 oz from the prospectus forecast of 300 000 oz to 340 000 oz.

It also flagged a substantial increase in the 2026 financial year growth capital for its Telfer operations to as much as $260-million, compared with the $80-million estimate outlined before its listing.

Greatland’s stock is trading nearly 24% lower than before the updated guidance was made public on July 29.

Greatland explained to the ASX that the capital cost increases followed a decision to accelerate mine extension works that were already flagged as potential opportunities in the prospectus. The original estimate was based on no further extensions beyond the 2026 and 2027 financial years, and excluded spending tied to potential life extensions.

Management has opted to bring forward projects previously targeted from 2028, including the West Dome Open Pit Stage 7 extension and West Dome Underground, to secure future ore sources, strengthen the production profile and reduce operational risk.

While it deemed the production and capital changes material, Greatland said it did not consider the increase in forecast all-in sustaining costs (AISC) – to as much as $2 800/oz from a midpoint of $2 500/oz – to be market-sensitive, given the mid-points of the AISC forecast ranges only increased by about 4%.

The company stressed that all updates remained incomplete and confidential until the board approved them, meaning disclosure obligations were not triggered earlier. “The updated production target, updated operating cost information and updated capital cost information . . . was not determined until after the board meeting,” it said.

Greatland confirmed it is in compliance with continuous disclosure obligations.