SpaceX files for its largest-ever IPO at $75 billion（約12兆円）, betting that Elon Musk's vertically-integrated space-and-AI stack will reshape orbital economics.

What happened: SpaceX filed to raise $75 billion（約12兆円） through an IPO—targeting 555.6 million shares at $135 each—which would be the largest IPO in history. The company is valued at roughly $1.75 trillion（約280兆円）. Tom Mueller, SpaceX's first employee and founder of orbital-transfer company Impulse Space, called the filing "finally," after Musk had long resisted going public.

Why it matters: The valuation reflects a bet that compute and data centers will move to space, and that Musk controls the full stack to make it happen: cheap rockets (Falcon 9), in-orbit computing proof from Starlink (which generated $11.39 billion（約1.8兆円） in 2025 revenue), and AI training data via xAI's Grok, Tesla robotics, and X. SpaceX posted $18.67 billion（約3兆円） in 2025 revenue but a $4.9 billion（約7800億円） net loss, with capital spending nearly doubled to $20.7 billion（約3.3兆円）—chiefly on AI. Mueller notes every past SpaceX milestone faced skepticism before succeeding.

What to watch: Mueller predicts the stock will follow Tesla's arc—a high opening, a "valley of death" when schedule delays become public-market news, then recovery. Meanwhile, Impulse Space is targeting a 2027 launch of its Helios spacecraft. The IPO also marks a reckoning in venture secondaries, as pre-IPO SpaceX shareholders via SPVs will need to clarify what they own.