Factorial Energy is a solid-state battery developer that went public on Nasdaq under the FAC ticker on June 8, 2026 after completing a SPAC merger with Cartesian Growth Corporation III. Solid-state batteries replace the liquid electrolyte in conventional lithium-ion cells with a solid material, potentially offering higher energy density, faster charging, and improved safety. Factorial has attracted strategic investment from major automakers as part of broader industry efforts to secure next-generation battery supply chains. The company's post-debut volatility reflects both the technical risk premium that markets assign to pre-revenue deep technology companies and the structural dynamics of SPAC-listed stocks in early trading.