According to Citadel Securities research data, in the third quarter, Microsoft, NVIDIA, Apple, and Meta collectively contributed approximately 300 points to the S&P 500 index's gain, more than three times the index's total gain during the same period; the remaining 496 companies collectively dragged it down by 150 points. Scott Rubner of Citadel pointed out that the stock market no longer represents ordinary stocks, and market concentration is approaching historical extremes.