SpaceX shares popped about 12% on Tuesday, as Elon Musk‘s rocket builder continued its meteoric rise following a record-breaking IPO on Friday.

With the skyrocketing share price, SpaceX briefly overtook Microsoft in market cap, becoming the fourth-largest company by valuation in the U.S.

SpaceX’s market cap touched $2.94 trillion in mid-morning trading, surpassing Microsoft’s valuation of $2.93 trillion, before finishing the day lower at $2.65 trillion.

SpaceX also leapfrogged Amazon, which has a market cap of about $2.64 trillion. The stock has a higher bar to clear to pass Apple, the third-largest U.S. company, with a market value of nearly $4.4 trillion.

The move comes after SpaceX shares jumped 20% in their first full day of trading…