The study deals with the issue of passive investing, with the aim of analyzing the behavior of share prices that enter one of the most important world indices S&P 500. The study deals specifically with nine shares that entered the index in 2024. Data on share prices were obtained via the Google Finance application interface. Using the linear regression method and ratio analysis of the relative change in share price, we analyzed the performance of the nine shares before entering the index and subsequently after their entry. The results of the work clearly demonstrated that shares that enter the S&P 500 index will subsequently record a positive growth in share price with a high probability. The results also indicate that the rate of share price growth increases after entering the index, however, the results are not so clear. At the same time, the results did not demonstrate a fundamental difference in the jump in share price in the case of the date of announcement of entry into the index and the date of actual entry.