Back in January 2015, Alphabet dropped $900 million on a stake in SpaceX. At the time, SpaceX was valued at roughly $12 billion. That investment bought Alphabet somewhere between 7% and 7.5% of the company.

Fast forward a decade, and that stake is now worth an estimated $100 billion to $111 billion. A roughly 100x return on a single investment.

The math behind the monster return

SpaceX is currently preparing for a much-anticipated IPO targeted for June 2026. The company is expected to go public at a valuation between $1.5 trillion and $1.8 trillion, with shares priced around $135 each.

At those numbers, Alphabet’s stake, even after dilution over multiple funding rounds that brought its ownership down to an estimated 5% to 7.4%, could be worth as much as $122 billion at the higher end of valuation estimates.

A partnership that goes beyond equity

The financial relationship between Alphabet and SpaceX isn’t limited to that 2015 equity stake. Alphabet has committed to paying SpaceX $920 million per month for AI compute capacity under a new agreement. That deal spans 32 months, starting in late 2026 and running through mid-2029, making it a contract worth north of $29 billion over its full term.

What the SpaceX IPO means for Alphabet investors

Once SpaceX is publicly traded, Alphabet will need to mark its position to market each quarter, which could introduce meaningful volatility to its earnings reports, both upward and downward, depending on how SpaceX stock performs post-listing.