Shares of Elon Musk's SpaceX surged at the opening on their first day of trading Friday. The company's $75 billion initial public offering made history, instantly propelling it into the ranks of the world's largest publicly traded firms.

At 11:46 a.m. New York time, the stock's first trade on the Nasdaq was at $150, marking an 11% premium over its $135 IPO price. It later climbed as high as $168.75. This price surge also made Musk the world's first trillionaire and pushed the company's market capitalization above $2 trillion.

Dec Mullarkey, Managing Director at SLC Management, commented, "The initial pop is within the normal range for tech stock volatility. It aligns with my expectations, as I believe the investor base includes both those who believe Musk has a Midas touch and technical traders. To some extent, they balance each other out."

SpaceX President Gwynne Shotwell, CFO Bret Johnsen, and Musk's mother, Maye, were present at the Nasdaq MarketSite for the listing ceremony, while Musk himself remained at the company's Starbase headquarters in Texas. Many SpaceX employees had other business to attend to: about an hour before U.S. markets opened, a SpaceX Falcon 9 rocket launched 29 Starlink satellites into orbit from Cape Canaveral, Florida.

"It's truly incredible that this little company that started in an El Segundo warehouse is now going public in the largest IPO in history," Musk said in a livestream on the X platform. "Honestly, if someone had told me all this would happen, I would have thought, 'Man, you must be on some strong stuff, because I thought this company would fail.'"

Despite the market's fervor for the listing, many investors remain skeptical about whether a company that is not yet profitable deserves such a lofty valuation.

"Fundamentally, investors are getting too excited," said Amanda Lyons, Head of Research at Energy Group Capital Group. She estimates SpaceX's valuation at roughly $600 billion on a sum-of-the-parts basis, about one-third of its IPO market cap. "But for Elon Musk, 'expensive' has never been a catalyst. Shorting the Musk premium has been a losing trade for the past decade."

On the other hand, long-time Musk bulls argue that the premium attached to his companies holds value.

"The SpaceX IPO marks an inflection point where the world is shifting from software-led to hardware-led," said Sequoia Capital partner Shaun Maguire, who led the firm's investments in Musk's companies. "This is true in the real economy, in venture capital, and in public markets. It's something that has been brewing behind the scenes for the past two or three years."

Friday's trading will be a critical test for SpaceX. Even after raising a record amount through its IPO, the company still needs the market to endorse its ambitions of dominating AI and sending humans to the moon and Mars, while also accepting its controversial governance structure, which grants Musk near-total control.