The Toronto-based company said adjusted profit for the three months ended September was US$18.4 million, or 11c per share, up from $4.1 million, or 3c per share, a year ago. Earnings came in better than average consensus forecasts calling for 5c per share, but revenue, up 13.4% yoy to $73.2 million, was light in terms of the forecast looking for $79.3 million.

The adjusted EBITDA of $37.2 million, a 72% jump yoy, was mainly attributable to improved sales and reflected higher output across all three operations and the higher realised prices.

CEO Luis Marchese ascribed the record EBITDA figure to improved operational efficiencies across the portfolio.

"The company continues to realise the benefits of our optimised operations and expansions ramp-up, which provides for stronger financial and operational performances which we expect to continue through the upcoming year," he said on a conference call.

"These improvements have enhanced the competitive position of both the Bolivar and Yauricocha mines within the cost curve for the global copper mining industry, with both mines now positioned in the lowest half of the cash cost curve.

"All things being equal, we expect higher EBITDA in 2021."

Copper output increased 9% yoy to 12.2Mlb, with silver and gold output for the quarter at 1Moz and 3,989oz, respectively. Zinc production came in 11% higher yoy at 24.9Moz and accounted for 20% of the quarterly revenues, with copper accounting for 37% and silver for 25% of the total, respectively.

All-in sustaining costs fell across the portfolio, except for Yauricocha, where the zinc-equivalent AISC rose 18% to $1.93/lb, given higher costs and capital spending amid a lower grade and recoveries. Bolivar produced copper-equivalent at AISC of $1.72/lb, down 32% yoy, and Cusi produced silver-equivalent at $16.47/oz, down 33% yoy.

Sierra reconfirmed its COVID-19-impacted full-year production guidance at between 110.1-122.3Mlb copper-equivalent, or 17.4-19.4Mlb on a silver-equivalent basis, but adjusted higher the full-year AISC for each operation. Sierra expects 2020 consolidated EBITDA of $100-105 million, compared with $65.3 million for 2019.

Shares in the company have increased by 60% over the past 12 months, last trading at C$2.79 per share, which capitalises Sierra at $454 million (US$350 million).