[Analysis: Chip Stock Weight Hits Historic High, Accounting for Nearly 20% of S&P 500, Raising Concentration Concerns] According to Deep Tide TechFlow, as of June 30, the weight of the chip sector in the S&P 500 index has risen to a record 19.7%, nearly quadrupling from 2020 levels, primarily driven by the investment boom in artificial intelligence (AI). With the continued expansion of AI infrastructure and computing power demand, chip stocks have become one of the core drivers of the current U.S. stock market rally. This has further concentrated the overall structure of the S&P 500 toward a few leading tech and chip companies, intensifying concerns about excessive index concentration and overvaluation. Nevertheless, continuous inflows into related ETFs are still supporting the sector's performance. Market participants are closely watching whether AI capital expenditures can continue to materialize to sustain the current valuation levels of semiconductors.