SpaceX stock sinks for a second day as company slips below Amazon in market cap

SpaceX shares dropped 3.57% on Thursday, as the stock's recent rally cooled following a record-breaking IPO last week.

Elon Musk's space and artificial intelligence firm became one of the world's most valuable companies after listing, and on Tuesday, its market cap surpassed Amazon and — briefly — Microsoft.

With Thursday's loss, SpaceX closed at a market cap of $2.43 trillion, slipping below Amazon, which ended the day up 2.9% with a cap of $2.63 trillion, among the most valuable companies in the U.S.

On Wednesday, shares sank 5%.

SpaceX saw its stock surge about 15% this week, with the market closed on Friday for the Juneteenth holiday. Shares were still up 37% after its historic debut last week, which offered shares at a set price of $135.

SpaceX shares over the past five days.

The rocket maker announced Wednesday that it's adding Musk's longtime friend and ally, Roelof Botha to the board.

Botha will serve as an independent director and a member of the company's audit committee, starting immediately. Botha becomes the eighth board member at SpaceX, where Musk serves as chairman, in addition to his roles as CEO and technology chief.

Musk ​controls more ⁠than 82% of voting rights at SpaceX and owns shares in the company worth over $1 trillion. The governance model gives outside shareholders little ability to exert influence.

Posting on X on Sunday, Musk said that the company "might be able to reach approximately" $1 trillion revenue in 2030.

— CNBC's Lora Kolodny helped contribute to this report.