Chinese equities fell sharply on Monday, September 28, 2026, with the Shanghai Composite Index sliding to its lowest level in over a year as technology and semiconductor shares led a broad selloff driven by a confluence of geopolitical headwinds, rising oil prices, and elevated U.S. Treasury yields.
The Shanghai Composite closed at 3,823.62 points, down 1.67 percent, or 64.75 points, from the previous session. The decline pushed the benchmark index to its weakest level since August 2025, marking a 13-month low. The Shenzhen Component fared worse, dropping 3.44 percent to 12,858.8, a nine-month trough. The CSI 300 blue-chip index lost 2.2 percent, while the STAR Market 50 — heavily weighted toward technology — plunged 4.1 percent, its steepest single-session drop in five weeks.
The selloff was concentrated in chipmakers and artificial intelligence hardware firms after a dual blow to the sector. Reports that Beijing is considering allowing companies such as ByteDance and Alibaba to purchase Nvidia's advanced H20 chips undercut the investment thesis for domestic semiconductor names, which had rallied on the premise of import substitution. Cambricon Technologies fell 6.55 percent, GigaDevice Semiconductor dropped 6.58 percent, and SMIC lost 3.6 percent, according to TradingEconomics data. In the optical components space, Zhongji Innolight declined 4.35 percent and Eoptolink Technology fell 4.53 percent, after four U.S. senators introduced legislation on September 25 to designate Chinese AI data center component suppliers as entities subject to government procurement restrictions.
Beyond sector-specific pressure, the macro backdrop remained hostile. Brent crude traded above $100 per barrel after U.S. President Donald Trump rejected an Iranian proposal regarding the Strait of Hormuz, sustaining fears of supply disruptions. The benchmark U.S. 10-year Treasury yield hovered near 5.20 percent, its highest since 2007, raising the discount rate applied to growth equities across Asia. The U.S.-China summit held the previous week had produced a limited agreement to reduce tariffs on roughly $30 billion of bilateral imports and extend the trade truce through January, but failed to address core issues including artificial intelligence cooperation, Taiwan, and the Iran conflict.
The Hang Seng Index in Hong Kong bucked the regional trend, closing up approximately 0.5 percent, as investors there priced in the tariff reduction and trade truce extension more favorably. Still, the divergence underscored the depth of pessimism on the mainland, where the Golden Week holiday — the week-long National Day break beginning October 1 — prompted pre-holiday positioning and profit-taking. Traders were reluctant to carry risk through an extended closure with no resolution to the tariff timeline or the Iran standoff.
July 2026 had already been the CSI 300's worst monthly performance in a decade, with an 8.6 percent drop fueled by global technology selloffs and profit-taking in domestic memory chipmakers. Monday's decline extended that pain, suggesting that the semiconductor sector remains caught between geopolitical crossfire and investor skepticism about the viability of Chinese alternatives to Western chip technology. With U.S. export policy serving as the single most important variable for Chinese tech stocks, any formal announcement regarding Nvidia H20 access — whether easing or tightening restrictions — could trigger further volatility.
Sources
- South China Morning Post, "Mainland Chinese stocks hit 13-month low on tech sell-off as Hong Kong market holds up," September 28, 2026. scmp.com
- Xinhua, "Chinese shares close lower Monday," September 28, 2026. english.news.cn
- TradingEconomics, "The Shanghai Composite Index Closes 1.70% Lower," September 28, 2026. tradingeconomics.com
