First Solar Drops ITC Trade Complaint Over TOPCon Patents, Shares Fall 5%

First Solar voluntarily withdrew its Section 337 trade complaint at the U.S. International Trade Commission targeting rival solar manufacturers over TOPCon solar cell intellectual property, sending shares down roughly 5% in Wednesday afternoon trading. The company characterized the withdrawal as procedural, saying it will continue pursuing the same patent claims through U.S. District Court lawsuits against the defendants.

First Solar had filed the ITC complaint on February 24, 2026, alleging that multiple manufacturers, including JinkoSolar and others, imported TOPCon solar products that infringed First Solar's patents, and had sought a broad exclusion order that would have barred those products from entering the United States. By dropping the ITC route, First Solar forfeits that powerful trade remedy but retains its district court cases, which carry different procedural timelines and remedies.

Enphase Energy also slipped on the news while Sunrun held steady. First Solar's stock underperformed the broader solar sector on Wednesday, with the market interpreting the withdrawal as at least a near-term setback in its effort to restrict competing TOPCon imports.