Palantir Technologies (PLTR) has officially joined the S&P 500, marking a significant milestone for the company. The inclusion in the index means that tens of millions of people who own S&P 500 retirement accounts and 401(k)s now hold a stake in Palantir. The stock has seen a remarkable rise, up 500% since 2022 and 128% year-to-date. Additionally, Palantir shares increased by 1.65% on the day of the announcement and 1.95% despite an analyst downgrade. The company is now in the S&P 500 Technology Services category. Notably, Stanley Druckenmiller, one of the top hedge fund managers, holds a position in the company, which has gained approximately 78% in less than two quarters. In a related development, Dell Technologies (DELL) has been relisted on the S&P 500, with its stock rising by 0.40% in pre-market trading.