Lumentum is trading 10.07% down at $871.34 after a broad technology and semiconductor selloff on August 18, 2026.
- Rising Treasury yields, oil above $90, and renewed U.S.-Iran tensions are driving risk-off positioning; the Philadelphia Semiconductor Index fell more than 5%.
- Reuters reported the 30-year Treasury yield reached 5.321%, its highest in almost 20 years.
- Lumentum announced an investor conference presentation, but no company-specific negative catalyst was identified.