硫酸行业保供稳价，碳酸锂、PTA涨幅居前

Market Performance - The basic chemical index increased by 2.58% from December 13 to December 19, while the CSI 300 index decreased by 0.28%, indicating that the basic chemical sector outperformed the CSI 300 by 2.85 percentage points, ranking fifth among all sectors [1][2] - The top-performing sub-industries included spandex (15.38%), other rubber products (10.78%), viscose (5.14%), civil explosives (4.25%), and potassium fertilizer (3.98%) [1][2] Chemical Price Trends - The top five products with the highest weekly price increases were hydrochloric acid (Jiangsu) at 57.14%, hydrochloric acid (Shandong) at 44.44%, industrial-grade lithium carbonate at 7.63%, battery-grade lithium carbonate at 7.57%, and butadiene at 6.12% [3] - The top five products with the largest weekly price declines included concentrated nitric acid at -9.30%, VCM (vinyl chloride monomer) at -6.25%, international gasoline at -6.11%, caustic soda (32% ion membrane) at -5.45%, and sulfur at -5.06% [3] Industry Dynamics - The sulfuric acid industry is focusing on supply stability and price control to ensure national food security, with measures being implemented to stabilize fertilizer supply and prices ahead of the spring farming season [4] - The current international sulfur supply is tight, leading to increased global sulfur resource prices and significantly raising the production costs for phosphate fertilizer [4] - As of December 19, the market price for sulfuric acid (98% smelting acid, Shandong) was 865 RMB/ton, with an increase of 8.81% in December and a year-to-date increase of 162.12% [4] Company Developments - Mitsui Chemicals announced an expansion of its MDI production capacity in South Korea, adding 100,000 tons/year, which will increase the plant's annual capacity from 610,000 tons to 710,000 tons, with production expected to start in May 2027 [5] - Dow Chemical plans to raise prices for its polymer MDI products in Southeast Asia by $200/ton, while Wanhua Chemical will also increase prices for all MDI and TDI products in Latin America by $200/ton starting December 15 [5] Investment Recommendations - The current investment focus includes the refrigerant sector, chemical fiber sector, and high-quality growth stocks, with specific companies recommended for attention [6] - Suggested companies in the refrigerant sector include Jinshi Resources, Juhua Co., and Sanmei Co. [6] - In the chemical fiber sector, recommended companies include Huafeng Chemical and Xinfengming [6] - Other notable companies include Wanhua Chemical, Hualu Hengsheng, and Luxi Chemical [6]