A-share Market Close | ChiNext Index Falls 1.10%, Lab-Grown Diamonds and MLCC Lead Gains

On September 14, the three major A-share indices opened lower collectively, turned positive across the board at one point during the session, then retreated after rising, and closed slightly lower collectively. The divergence between the yellow and white lines was obvious, with small- and mid-cap stocks outperforming heavyweight stocks. The Shanghai Composite Index closed at 3885.33 points, down 0.07%; the Shenzhen Component Index closed at 13384.57 points, down 0.64%; the ChiNext Index closed at 3285.58 points, down 1.10%; the STAR 50 Index closed at 1528.27 points, down 1.62%; the BSE 50 Index closed at 1021.90 points, down 0.15%. Turnover in the Shanghai and Shenzhen markets was 1,629.176 billion yuan, a decrease of 342.723 billion yuan from the previous trading day. In the Shanghai and Shenzhen markets, 3,126 stocks rose, 2,224 fell, and 212 were flat, of which 57 hit the daily limit up and 18 hit the daily limit down, with rising stocks accounting for about 56%. By sector, concept sectors such as lab-grown diamonds, CRO, MLCC, medical services, PCB, and cybersecurity led the gains; sectors such as planting and forestry, tourism and hotels, military equipment, coal, and diversified finance led the declines. Drivers On that day, index performance and the distribution of stock gains and losses were not consistent. The Shanghai Composite Index and Shenzhen Component Index fell 0.07% and 0.64%, respectively, while the ChiNext Index and STAR 50 fell 1.10% and 1.62%, respectively, yet 3,126 stocks in the Shanghai and Shenzhen markets rose, accounting for about 56%; turnover in the two markets was 1,629.176 billion yuan, a decrease of 342.723 billion yuan from the previous trading day, showing a clear contraction in volume. On the news front, the lab-grown diamond segment was driven by research reports from institutions such as Huaxi and Founder regarding diamond's thermal conductivity advantages and the accelerated industrialization of diamond-copper in AI chip cooling; the MLCC segment was affected by supply contraction expectations after Murata Manufacturing announced it would discontinue some part numbers in fiscal 2026; the pharmaceutical segment was driven by a CITIC SEC research report stating that China's CDMO industry has entered an era driven by the dual cores of the "engineer dividend" and the "leading innovation dividend"; the cybersecurity concept was affected by news that Anthropic's CEO called for slowing the development of frontier models and that heads of several overseas AI companies expressed support; in addition, the automobile sector rebounded that day, with Anhui Ankai Automobile, Zotye Automobile, and Haima Automobile hitting the daily limit up. Among popular sectors 1. [Lab-Grown Diamonds] The lab-grown diamond concept rose 4.77%, ranking among the top concept sectors. Henan Huanghe Whirlwind and Hengsheng Energy hit the daily limit up, Inno Laser Technology rose more than 15%, HFZS rose more than 10%, and Henan Liliang Diamond and Sf Diamond Co., Ltd. followed the gains. In terms of catalysts, a Huaxi research report pointed out that diamond's thermal conductivity is more than 5 times that of copper and is an important upgrade direction for AI chip cooling, and estimated that from 2026 to 2030 the global diamond cooling market's neutral-case compound annual growth rate would be about 128%; Cailian Press, citing institutional research reports, said that from 2025 to 2029 the global AI chip diamond-copper market compound growth rate is expected to reach 237%, with market space expected to expand to US$6.5 billion. In addition, the periodic adjustment of BSE 50 Index sample stocks took effect on September 14, and HFZS was included. 2. [MLCC] The MLCC concept surged that day. Jiangsu Shuangxing Color Plastic New Materials recorded a second consecutive daily limit up, Kangda New Materials hit the daily limit up, and Guangdong Fenghua Advanced Technology, Shandong Sinocera Functional Material, Suzhou Gyz Electronic Technology, Shandong Chunguang Technology Group, and others followed the gains. In terms of catalysts, MLCC leader Murata Manufacturing issued an official notice announcing the launch of product line optimization in fiscal 2026, discontinuing some part numbers in consumer-grade conventional series and automotive specification series, covering the GRM, GRJ, GRT, GXM, GXT, GCM, GCJ, GCG, and ZRA series. Market analysis believes it intends to free up capacity and prioritize high-value-added products for AI servers. Separately, according to Yicai, Samsung Electro-Mechanics signed a contract worth 1.07 trillion won (about 5.333 billion yuan) in early September with a major global company for AI server MLCC supply. 3. [Pharmaceuticals/CRO] The pharmaceutical segment strengthened collectively. The medical services sector rose 4.65%, ranking first among industry sectors, and the CRO concept rose 4.89%. Anhui Wanbang Pharmaceutical Technology and Novoprotein Scientific Inc. both hit the 20CM daily limit up, while GemPharmatech, PharmaBlock Sciences, Asymchem Laboratories, Sino Biological, Inc., and others followed the gains. In terms of catalysts, a CITIC SEC research report said that as new blockbuster drugs, new molecules, and new technologies raise requirements for process development and trial design capabilities, China's CDMO industry is expected to enter an era driven by the dual cores of the "engineer dividend" and the "leading innovation dividend" by leveraging its accumulation in early-stage pipelines in the global biopharmaceutical innovation technology field; in addition, the 2026 World Conference on Lung Cancer was held in Seoul, South Korea, from September 12 to 15, where multiple domestic pharmaceutical companies concentrated on disclosing clinical data. Adjusting sectors The planting and forestry sector pulled back that day, with Gansu Dunhuang Seed Group, Xinjiang Talimu Agriculture Development, Gansu Yasheng Industrial, and Cofco Biotechnology hitting the daily limit down; the tourism and hotels sector opened lower and moved lower, with Yunnan Tourism and Xi'an Qujiang Cultural Tourism hitting the daily limit down; the military equipment segment weakened, and the military restructuring concept pulled back, with Jianshe Industry Group closing down 7.66% and Changshu Guorui Technology closing down 6.38%. Marine equipment II fell 1.99%, and national defense and military industry fell 1.70%. Among them, the ground armament sector had closed up 4.44% on September 11, leading the entire market, and that day turned into one of the top decliners; coal and diversified finance sectors also pulled back slightly.