Shares in Horizonte Minerals PLC (AIM:HZM, TSX:HZM, OTC:HZMMF) plummeted 60% following the announcement that the bill to finish its Brazillian nickel mine had almost doubled to $1 billion.
This revised figure rises from a previous estimate of $537 million and was provided by G Mining Services, a specialist in mining construction and engineering. According to interim chief executive Karim Nasr, the cost to complete the Araguaia mine is now built on "solid methodologies".
Despite the setback, Horizonte expects to operation to spit out its first metal early in 2026, which looks optimistic given the additional cash required is yet to be found.
In an update pushed out after hours on Monday, the mine developer said it is working with its major shareholders and senior lenders on a full funding solution, which is expected to be in place by the end of June at the latest.
The latest collapse in the share price - down 5.1p at 3.4p - values the business at just over £9 million. Less than 18 months ago, the business was worth £500 million.
But, a catalogue of setbacks has seen the valuation rapidly eroded as it has been left struggling to finance an enormous mine in the middle of nowhere in Brazil's Cerrado savanna, the country’s second-largest ecosystem after the Amazon rainforest.