报告为高盛美国市场周报（Portfolio Strategy）。近月利率上行与融资成本担忧令股市下调增长预期，投资者大幅减仓放大波动：过去两周周期股相对防御股组合下跌6%，10年期美债收益率回落逾20bp，高收益信用利差走阔逾20bp，其中AI相关发行人压力最大。基准情形预计2027年增长放缓但仍稳健：标普500每股盈利2026年增长36%、2027年放缓至11%（剔除会计扭曲后为18%）；AI资本开支目前约贡献标普500盈利增长的一半，其推动力将于2027年减弱。三季度财报初期显示53%公司盈利超预期一个标准差，高于50%的长期均值但低于过去四季度的64%，盈利上修广度亦收窄。历史上正增长但减速的环境下，指数回报为正但趋缓且主要由盈利而非估值驱动，信息科技与医疗保健占优，材料与可选消费落后，动量、盈利上修与低波因子有效。
Rising funding costs and intensifying rate pressure have led the equity market to downgrade its growth outlook, with a sharp reduction in investor positioning amplifying moves: the Cyclicals vs. Defensives pair fell 6% in two weeks, the 10-year Treasury yield dropped more than 20 bp while USD high yield spreads widened more than 20 bp, concentrated in AI-related issuers. Our baseline embeds slowing but still solid growth in 2027: S&P 500 EPS growth of 36% in 2026 slowing to 11% in 2027 (18% adjusting for accounting distortions). AI capex currently contributes roughly half of S&P 500 EPS growth, an impulse that should fade into 2027 as capex growth slows and depreciation builds. The early Q3 read supports peak growth and revision rates: 53% of firms have beaten consensus EPS by a standard deviation versus the 50% long-term average and 64% over the past four quarters, and revision breadth has moderated. Positive but decelerating growth has historically meant positive but moderating retur