Aehr Test Systems is trading 4.21% down at $100.00 in pre-market amid technology and semiconductor weakness. - No company-specific announcement explaining the September 28, 2026 pre-market decline was found; the latest identified official release was September 3. - Coverage linked overnight sector weakness to OpenAI pausing work on some advanced AI models and renewed Iran tensions. - Broader futures fell, but supplied index moves were below 0.5%; no confirmed company catalyst emerged.