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.

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,

In a week when the broad market rally lost some steam, Palantir Technologies Inc. (NYSE: PLTR) ended the week on a tear. PLTR stock was up 9.13% at the close of trading on November 15. The catalyst for the price movement was the announcement that Palantir was leaving the New York Stock Exchange and would be listed on the NASDAQ exchange.