Ses AI (NYSE: SES) plunges 6.28% as investors unwind holiday-driven rally gains amid mixed corporate signals.

Ses AI (NYSE: SES) plunged 6.28% in pre-market trading on Dec. 31, 2025, marking its third consecutive day of declines as investors continue to unwind positions following a holiday-driven rally. The selloff reflects profit-taking amid mixed signals from recent corporate developments.

The company recently showcased its upgraded Molecular Universe (MU-1.5) platform at the 5th annual Battery World conference, highlighting advancements in proprietary molecular databases. However, the market appeared unimpressed by the technical progress, with shares failing to hold gains despite the product reveal.

A strategic partnership with Top Material to expand battery manufacturing capacity for drones and urban air mobility (UAM) applications in South Korea was also announced. The collaboration aims to strengthen SES AI’s supply chain compliance with U.S. defense regulations and meet rising demand in advanced mobility sectors. CEO Qichao Hu emphasized the partnership’s role in scaling production, though the timing of the first-quarter 2026 agreement has yet to materialize into near-term investor confidence.

The sustained downward pressure suggests market skepticism about the company’s ability to translate R&D milestones and strategic alliances into consistent profitability. Analysts note that while the long-term potential in AI-driven battery solutions remains, short-term volatility is likely to persist as the stock digests recent momentum.