Shares of Sigma Lithium Corporation (SGML) are soaring 5.31% in Friday's pre-market trading, despite reporting lower-than-expected second-quarter earnings. The surge comes as investors focus on the company's strong production figures and effective cost management strategies.

Sigma Lithium reported a quarterly loss of 17 cents per share, wider than the analyst forecast of a 10-cent loss. Revenue fell 73.1% year-over-year to C$16.89 million, significantly below the expected C$37.00 million. However, the company achieved lithium oxide concentrate production of 68,368 tonnes in Q2 2025, a 38% year-on-year increase and slightly above the quarterly target of 67,500 tonnes.

Investors appear encouraged by Sigma Lithium's cost control measures. The company reported CIF China cash operating costs of $442/t in Q2, 12% below the target of $500/t. All-in sustaining cash costs (AISC) totaled $594/t, 10% below the target of $660/t. These cost reductions were driven by economies of scale, stable plant gate costs, and efficient logistics. Additionally, Sigma Lithium remains on track with its Phase 2 expansion project, which aims to double its nameplate capacity to 520,000 tonnes per year. The company's strong operational performance and future growth prospects seem to be outweighing the earnings miss in investors' minds, contributing to the stock's significant pre-market rally.