2025 W30 - Retail-Driven Speculative Frenzy Reignites S&P 500 Index Inclusion Effect - 散户驱动的投机热潮重燃标普500指数纳入效应

Key Logic

The recent retail-driven speculative frenzy in the US equity market, manifested through a surge in trading volume of unprofitable, penny, and high-multiple stocks, elevated call option activity, heightened social media sentiment, and short squeezes, has significantly reignited the S&P 500 Index Inclusion Effect. This is particularly evident in the migration of non-S&P 400 mid-cap stocks and retail-favored stocks associated with hot themes like AI. While the outperformance driven by this inclusion effect primarily occurs pre-announcement and lacks persistence, it signals potential upside risks for the equity market in the short term, but may increase market downside risks over the long term (24 months). Concurrently, the narrow market breadth suggests that intra-market sector rotation may continue.

近期US equity market由散户驱动的投机热潮，通过无盈利、低价股和高估值股票交易量激增、看涨期权活跃、社交媒体情绪高涨以及空头挤压等多种形式，显著重燃了S&P 500指数纳入效应，尤其体现在非S&P 400中型股迁移、受散户青睐且与AI等热门主题相关的股票上，尽管这种纳入效应带来的超额收益主要发生在公告前且不具持久性，但短期内预示着股市潜在上行风险，而长期（24个月）则可能增加市场下行风险，同时狭窄的市场广度也预示着市场内部板块轮动可能持续。