Longtime activist investor Carl Icahn sold his stake in Lyft prior to its initial public offering last week, according to sources familiar with the matter.

Icahn's stake in Lyft amounted to about 2.7 percent of the ride-hailing company. Though it wasn't clear what price he received for the stake, the investment was worth roughly $550 million at the IPO price, according to the Wall Street Journal, which first reported that he had dumped the stake.

When Icahn first bought his stake four years ago, his take was worth $100 million in the then-private company. At the time of the initial investment, Icahn said he believed that increasing urbanization over the next five-to-ten years should continue the company's revenue growth.

Icahn did not immediately respond to CNBC's request for comment.

Though the stock finished its first session at $78.29, above its IPO price of $72, it was last seen trading at $70.31 after falling nearly 12 percent on Monday. It was worth more than $22 billion when it went public last week, despite the fact that it posted a net loss of nearly $1 billion in 2018.