Sigma Lithium Corporation (NASDAQ:SGML) saw its stock surge 5.59% in after-hours trading on Monday, following the release of its fourth-quarter earnings report. Despite missing revenue expectations, the company demonstrated substantial growth and operational improvements that have impressed investors.

The lithium producer reported Q4 revenue of C$67.206 million, which, although falling short of the C$73.025 million consensus, represented a remarkable 127% sequential increase in USD terms. Sigma Lithium's production efficiency saw a significant boost, with output rising 28% to 77,034 tonnes of its Quintuple Zero Green Lithium concentrate. The company also reported strong profitability metrics, including a cash gross margin of 42% and an Adjusted EBITDA of $12.3 million, with a 26% EBITDA margin.

Investors appear to be particularly encouraged by Sigma Lithium's cost-cutting measures and operational efficiency gains. The company reduced its CIF China cash operating costs by 17% to $427 per tonne and reported all-in sustaining costs (AISC) of $592 per tonne. Additionally, Sigma Lithium's ambitious growth plans, including the construction of a second Greentech Industrial Plant to double production capacity in 2025, have likely contributed to the positive market reaction. The company's outlook for 2025, projecting production of at least 270,000 tonnes of lithium concentrate while maintaining competitive cost structures, further bolsters investor confidence in its long-term prospects.