Group 1: Index Movements - On December 15th, the Shanghai Composite Index dropped by 0.55% to close at 3867.92 points, with a trading volume of 764.605 billion yuan; the Shenzhen Component Index fell by 1.1% to close at 13112.09 points, with a trading volume of 1008.835 billion yuan [1]. - The CSI 1000 Index decreased by 0.84%, with a trading volume of 372.659 billion yuan, opening at 7324.48, closing at 7309.08, reaching a high of 7375.61 and a low of 7305.83 [1]. - The CSI 500 Index declined by 0.78%, with a trading volume of 301.024 billion yuan, opening at 7121.38, closing at 7113.96, reaching a high of 7177.15 and a low of 7110.68 [1]. - The SSE 50 Index dropped by 0.25%, with a trading volume of 111.134 billion yuan, opening at 2979.76, closing at 2987.07, reaching a high of 3015.39 and a low of 2978.13 [1]. Group 2: Impact of Sector Movements on Indexes - The CSI 1000 Index dropped 61.86 points from the previous close, with sectors such as Medicine & Biology, Communication, and Electronics significantly dragging down the index [2]. - The CSI 500 Index fell 55.83 points from the previous close, with National Defense & Military Industry pulling the index up, while Electric Equipment, Machinery, and Electronics dragging it down [2]. - The SSE 50 Index decreased 7.57 points from the previous close, with Non - Banking Finance, Food & Beverage, and Basic Chemicals pulling the index up, while Machinery, Medicine & Biology, and Electronics dragging it down [2]. Group 3: Stock Index Futures Basis and Annualized Opening Costs - For IM contracts, IM00 had an average daily basis of - 8.87, IM01 of - 85.92, IM02 of - 246.25, and IM03 of - 490.68 [13]. - For IC contracts, IC00 had an average daily basis of - 2.63, IC01 of - 57.67, IC02 of - 174.09, and IC03 of - 377.5 [13]. - For IF contracts, IF00 had an average daily basis of - 5.33, IF01 of - 22.13, IF02 of - 48.54, and IF03 of - 92.24 [13]. - For IH contracts, IH00 had an average daily basis of - 2.95, IH01 of - 9.76, IH02 of - 10.95, and IH03 of - 26.66 [13]. Group 4: Stock Index Futures Roll - over Point Differences and Annualized Costs - For the IF contract, at 09:45, the point differences for IF00 - 01, IF00 - 02, and IF00 - 03 were - 15.1878, - 37.2969, and - 81.8414 respectively [24]. - For the IH contract, at 09:45, the point differences for IH00 - 01, IH00 - 02, and IH00 - 03 were - 5.45767, - 9.03133, and - 23.7498 respectively [25]. - For the IM contract, at 09:45, the point differences for IM00 - 01, IM00 - 02, and IM00 - 03 were - 75.8461, - 236.345, and - 480.077 respectively [27]. - For the IC contract, at 09:45, the point differences for IC00 - 01, IC00 - 02, and IC00 - 03 were - 55.5207, - 175.242, and - 383.666 respectively [28].