InterDigital is trading 4.1% up at $349.52, with no new company-specific announcement clearly explaining the after-hours gain.
- InterDigital closed at $335.77 on August 18, 2026.
- Its latest major catalyst was the July 30 earnings beat and raised 2026 guidance, which predates this move.
- The broader market was weak on August 18, making a market-driven explanation less convincing; recheck for delayed company news.