Shares of Palantir Technologies were trading lower Monday, but stock of the software company still boasts incredible gains this year. The software stock fell 9.8% to $59.30 and was on track for its largest daily percentage decrease since May,

Among those selling the stock was CEO Alex Karp, who filed to sell 4.5 million shares of the stock on Friday, which has a market value of $266 million. That sale was predetermined by a 10b5-1 plan, which sells stock at set intervals to avoid suspicions of insider trading. Palantir stock was down 5.38% as of 11:45 a.m. ET.

Palantir Technologies, the newest S&P 500 member, was the index's best performer in 2024 as of Nov. 15. But that didn't last.Nvidia was the biggest S&P 500 leader in 2023 and ruled for much of 2024, but power generation firm Vistra took the crown in September.