Shares of SIGA Technologies Inc. (NASDAQ: SIGA) tumbled 8.20% in after-hours trading on Thursday following the release of its disappointing third-quarter financial results. The commercial-stage pharmaceutical company, known for its antiviral drug TPOXX, reported a significant decline in revenue and a shift to net loss, raising concerns among investors about its near-term growth prospects.

SIGA's Q3 revenue plummeted to $2.62 million, a stark 73.83% decrease from $10.01 million in the same period last year. The company attributed this substantial decline primarily to lower product sales, especially reduced deliveries of its flagship product, TPOXX. Consequently, SIGA reported a quarterly loss of $0.09 per share, a dramatic reversal from the $0.02 per share profit recorded in the previous year's quarter.

Despite the weak quarterly performance, SIGA highlighted some positive developments for the first nine months of 2025. The company generated $53 million in oral TPOXX revenues and $26 million in IV TPOXX revenues from deliveries to the U.S. Strategic National Stockpile. Additionally, SIGA made a $6 million oral TPOXX sale to an international customer. However, these achievements were not enough to offset the significant Q3 decline. As SIGA focuses on securing new procurement contracts for future revenue growth, investors seem wary of the company's ability to maintain consistent financial performance in the face of fluctuating government and international orders for its antiviral products.