1 多箭齐发！中方坚决反制美"对等关税" 美东时间4月2日，美方宣布对所有贸易伙伴征收"对等关税"。中方对此坚决反对，并表示将坚决采取反制措施维护自身权益。4月4日，中方接连表态并发布反制行 动： 国务院关税税则委员会公告，对原产于美国的所有进口商品，在现行适用关税税率基础上加征34%关税； 商务部会同海关总署对钐、钆、铽、镝、镥、钪、钇等7类中重稀土相关物项实施出口管制措施； 中方在世贸组织起诉美"对等关税"措施； 商务部将斯凯迪奥公司等11家美国企业列入不可靠实体清单； 商务部将16家美国实体列入出口管制管控名单； 商务部对进口医用CT球管发起产业竞争力立案调查； 商务部对原产于美国、印度的进口相关医用CT球管发起反倾销立案调查； 海关总署暂停美国C&D (USA) INC.企业高粱和American Proteins inc.等3家企业禽肉骨粉输华资质； 海关总署暂停美国2家禽肉企业产品输华。 5 程序化交易规则落地！三大交易所细化监管标准 2 特朗普回应股市崩盘 在美国宣布所谓"对等关税"政策引发美国和全球股市震荡后，美国总统特朗普最新在社交媒体上转发其支持者发布的一段视频，视频开头表示 股市崩盘是" ...

Core Viewpoint - The phenomenon of end-of-day price surges on stock index futures settlement days is driven by various market mechanisms and investor behaviors, which need to be understood in a comprehensive manner [1]. Group 1: Settlement Price Mechanism - The settlement price for stock index futures is typically based on the arithmetic average of the underlying index over the last 1-2 hours on the expiration date, such as the last 2-hour average for the CSI 300 index [4]. - Investors may engage in concentrated trading at the end of the day to "manipulate" the settlement price, especially if they believe it will impact their profits or losses from open positions [4]. Group 2: Position Adjustment and Liquidity Changes - On settlement days, there is pressure to close positions as open contracts must be settled in cash at the settlement price, leading some investors to close positions at the end of the day to avoid physical delivery or optimize settlement costs [6]. - As the market approaches closing time, some investors may exit, resulting in reduced liquidity, which can significantly impact prices and create "surge" or "crash" scenarios [6]. Group 3: Arbitrage and Futures-Spot Linkage - As the settlement date approaches, futures prices typically converge towards the spot index, and if futures are trading at a discount, arbitrageurs may buy futures and sell the spot to drive up futures prices and narrow the basis [7]. - Algorithmic trading may trigger automated arbitrage strategies based on basis and volatility indicators at specific times, exacerbating short-term price fluctuations [7]. Group 4: Market Psychology and Expectation Games - Some traders may anticipate fund movements on settlement days (such as institutional rebalancing or retail investor behavior) and position themselves accordingly, influencing end-of-day market activity [8]. - Investors with information advantages, such as knowledge of large clients' positions, may exploit this information at the end of the day for profit [8]. Group 5: Potential Manipulation Risks - Abnormal price fluctuations at the end of the day can raise suspicions of manipulation, particularly if there are efforts to inflate the settlement price in conjunction with spot holdings for profit, which may violate trading regulations [9]. - Regulatory bodies typically increase monitoring of trading activities on settlement days to prevent such manipulative behaviors [9].