Shares of Sigma Lithium Corporation (SGML) surged 5.59% in after-hours trading on Monday, following the release of its fourth-quarter earnings report. While the company missed revenue expectations, investors appeared to focus on the significant production growth and positive outlook for 2025.

Sigma Lithium reported fourth-quarter revenue of C$67.206 million, falling short of the consensus estimate of C$73.025 million. However, the company demonstrated strong operational improvements, with total revenues in USD rising 127% sequentially to $47.3 million. The Greentech Plant upgrade led to a 28% increase in production, reaching 77,034 tonnes in the quarter.

Cost reduction efforts proved successful, with the company lowering its CIF China cash operating costs by 17% to $427 per tonne. Sigma Lithium also reported a robust cash gross margin of 42% and an Adjusted EBITDA of $12.3 million, highlighting improved profitability and operational efficiency.

Looking ahead, Sigma Lithium provided an optimistic outlook for 2025. The company expects to maintain competitive cost structures and projects production of at least 270,000 tonnes of its Quintuple Zero Lithium Concentrate. This forward-looking guidance, coupled with ongoing expansion plans, appears to have boosted investor confidence, driving the stock's after-hours rally.