Market Overview - The Shanghai Composite Index experienced fluctuations throughout the day, while the ChiNext Index saw a rise followed by a decline. The coal and gas sectors continued to surge, with multiple stocks such as Zhengzhou Coal Electricity and Guo Xin Energy hitting the daily limit. The trading volume reached 1.75 trillion yuan, a decrease of over 200 billion yuan compared to the previous trading day [1]. Hot Topics Cultivated Diamonds - The cultivated diamond sector saw significant gains in the afternoon, with stocks like Hengsheng Energy, Sifangda, and Huanghe Xuanfeng hitting the daily limit. This surge was catalyzed by the announcement from the Ministry of Commerce and the General Administration of Customs regarding export control measures on superhard materials, effective from November 8 [4]. Coal Sector - The coal sector experienced a substantial rise, with stocks such as Dayou Energy and Antai Technology achieving consecutive daily limits. The latest report indicated a notable increase in port coal prices, with the price of thermal coal at northern ports rising to 748 yuan per ton, an increase of 39 yuan per ton week-on-week [7]. Optical Communication - The optical communication sector rebounded, with stocks like Cambridge Technology and Huylin Ecological hitting the daily limit. Recent research indicated that the optical module and PCB indices had adjusted for 13 trading days, with declines of 17% and 16%, respectively. Citigroup noted potential upward demand for optical modules, predicting a rise in industry demand from 8 million units to over 20 million units by 2026 [9][10]. Stock Performance Cultivated Diamonds - Hengsheng Energy (605580.SS) closed at 30.03 yuan, up 10.00% with a market cap of 8.408 billion yuan. Sifangda (300179.SZ) rose by 19.98% to 14.05 yuan, with a market cap of 5.277 billion yuan. Huanghe Xuanfeng (600172.SS) increased by 10.00% to 6.38 yuan, with a market cap of 8.143 billion yuan [5]. Coal Stocks - Dayou Energy (600403.SS) closed at 7.26 yuan, up 10.00%, with a market cap of 17.357 billion yuan. Antai Technology (600408.SS) rose by 10.10% to 3.27 yuan, with a market cap of 3.292 billion yuan. Zhengzhou Coal Electricity (600121.SS) increased by 10.10% to 5.45 yuan, with a market cap of 6.640 billion yuan [8]. Optical Communication Stocks - Cambridge Technology (603083.SS) closed at 108.25 yuan, up 10.00%, with a market cap of 29.013 billion yuan. Huylin Ecological (001267.SZ) rose by 10.02% to 16.25 yuan, with a market cap of 9.850 billion yuan. Ruisi Kanda (603803.SS) increased by 9.99% to 8.92 yuan, with a market cap of 3.790 billion yuan [10].

Industry Overview - The Ministry of Commerce and the General Administration of Customs announced export control measures on five categories, including superhard materials, rare earth equipment, and lithium battery materials, effective from November 8 [1] - The production and sales ratio of superhard materials in China remains high, indicating a balanced supply-demand relationship and strong market absorption capacity [1] - The production and sales ratio for diamond wire and micro-powder products is close to 100%, reflecting strong demand in mature application scenarios such as photovoltaics and grinding [1] - PCD and PCBN tools, along with superhard grinding wheels, maintain a production and sales ratio of around 95%, indicating stable penetration in traditional manufacturing and precision processing [1] - The production and sales ratio for CVD diamond films is at 75%, with significant growth potential, and the market size is expected to exceed 5 billion yuan by 2030, driving the industry towards high value-added sectors [1] Company Insights - Sifangda has established a strategic product system centered on composite superhard materials, with precision diamond tools and CVD diamonds as new growth points [2] - Huanghe Xuanfeng is a leading company in the superhard materials industry, primarily producing cultivated diamonds and industrial diamonds [2]