Concentration. Even though the S&P five hundred is inherently diversified, it is becoming extremely concentrated in recent years, meaning that a little amount of the 500 corporations make up a significant percentage of the whole value of the index by itself. This example is from Wikipedia and should be reused https://retirementaccountdiversif19639.blog-eye.com/37954447/5-simple-statements-about-inflation-resistant-assets-explained