Ecovyst is trading 8.6% up in after-hours trading at $11.55, with the move appearing most consistent with broader risk-on sentiment.
- Ecovyst closed at $10.64 on September 17, 2026.
- No clear company-specific announcement or earnings release was identified for September 17.
- The S&P 500 gained 1.05% and the Nasdaq rose 1.68%, although futures were modestly lower later in the evening.