期指：宽松预期加持，偏强震荡

1. Report Industry Investment Rating - Not provided in the report 2. Core Viewpoints - On December 18, all four major stock index futures contracts for the current month declined. The overall trading volume of stock index futures decreased, indicating a cooling of investors' trading enthusiasm. The overall open interest of each index also decreased. The market is affected by factors such as A - share index differentiation, policy information at home and abroad, and central bank decisions [1][2] 3. Summary by Relevant Content 3.1 Stock Index Futures Data Tracking - CSI 300 and Related Futures: The CSI 300 index closed at 4552.8, down 0.59%. The IF2512 contract closed at 4550.4, down 0.73%, with a basis of - 2.39, and its trading volume decreased by 31440 and open interest decreased by 24245 [1] - SSE 50 and Related Futures: The SSE 50 index closed at 2998.5, up 0.23%. The IH2512 contract closed at 2995, down 0.02%, with a basis of - 3.52, and its trading volume decreased by 13480 and open interest decreased by 11717 [1] - CSI 500 and Related Futures: The CSI 500 index closed at 7100.8, down 0.52%. The IC2512 contract closed at 7101, down 0.71%, with a basis of 0.16, and its trading volume decreased by 29672 and open interest decreased by 22568 [1] - CSI 1000 and Related Futures: The CSI 1000 index closed at 7272.4, down 0.22%. The IM2512 contract closed at 7275.4, down 0.26%, with a basis of 3, and its trading volume decreased by 45179 and open interest decreased by 35409 [1] 3.2 Trading Volume and Open Interest Changes - Trading Volume: The total trading volume of IF decreased by 43587 lots, IH by 16253 lots, IC by 38325 lots, and IM by 65504 lots [2] - Open Interest: The total open interest of IF decreased by 7327 lots, IH by 8002 lots, IC by 8257 lots, and IM by 18274 lots [2] 3.3 Top 20 Member's Open Interest Changes in Stock Index Futures - For IF contracts, the long positions of IF2512 decreased by 16327, and the short positions decreased by 19569 with a net change of - 4749 in short positions [5] - For IH contracts, the long positions of IH2512 decreased by 8781, and the short positions decreased by 9176 with a net change of - 5721 in short positions [5] - For IC contracts, the long positions of IC2512 decreased by 16708, and the short positions decreased by 18402 with a net change of - 5523 in short positions [5] - For IM contracts, the long positions of IM2512 decreased by 25000, and the short positions decreased by 28272 [5] 3.4 Market Trends and Driving Factors - Trend Intensity: The trend intensity of IF and IH is 1, and that of IC and IM is also 1 [6] - A - share Market: A - share market showed differentiation. The Shanghai Composite Index rose 0.16% to 3876.37 points. The Shenzhen Component Index fell 1.29%, and the ChiNext Index fell 2.17%. The total trading volume of A - shares was 1.68 trillion yuan, down from 1.83 trillion yuan the previous day [6] - Hong Kong Stock Market: The Hang Seng Index rose 0.12% to 25498.13 points, the Hang Seng Tech Index fell 0.73% to 5418.29 points, and the Hang Seng China Enterprises Index fell 0.02% to 8841.51 points. The market trading volume was HK$1623.77 billion, down from HK$1831.41 billion the previous day [7] - Policy Information: The National Development and Reform Commission will take measures to expand effective investment. Trump said that the next Fed chair nominee will support "substantial" rate cuts [7] - Central Bank Decisions: The European Central Bank maintained the benchmark interest rate at 2% for the fourth consecutive time. The Bank of England cut interest rates by 25 basis points to 3.75% [7][8] - US Stock Market: The three major US stock indexes rose. The Dow Jones Industrial Average rose 0.14% to 47951.85 points, the S&P 500 Index rose 0.79% to 6774.76 points, and the Nasdaq Composite Index rose 1.38% to 23006.36 points [8]