China’s A-share market suffered a broad sell-off on the first trading day after the Mid-Autumn Festival holiday, with technology stocks bearing the brunt. The Shanghai Composite Index fell 1.67% and the Shenzhen Component Index dropped 3.44% at the September 28 close, while optical communications stocks across mainland and Hong Kong markets also declined sharply. Optical module leaders that had advanced in a sustained rally fell collectively, including three stocks the market had grouped under a name beginning with "Yi."