Interestingly, the structural characteristics of the US stock market are becoming increasingly apparent. The seven most influential companies within the S&P 500 contribute only a quarter of the total profits, yet their market capitalization accounts for as much as 36%—this figure alone illustrates how concentrated the market is.

Even more noteworthy are the forecast data. According to market estimates, these seven large-cap stocks are expected to contribute 46% to the earnings growth of the S&P 500 by 2026. In other words, the overall index's growth momentum will heavily depend on the profitability performance of these leading companies. This means that their performance fluctuations have a significant impact on the entire market—once these industry giants' profit growth slows down, the overall growth outlook of the market could be easily affected.

For investors, this reflects that the US stock market still operates primarily under the influence of large tech stocks, while the overall macroeconomic performance appears relatively secondary.