Tesla Inc. (TSLA) reported stronger second-quarter earnings on Wednesday, but one of the biggest contributors to its profit wasn't higher vehicle sales, energy storage or services. It was Space Exploration Technologies Corp. (SPCX).

Buried in Tesla's earnings report's cash flow statement is a $1.005 billion pretax unrealized gain on its SpaceX investment, equal to $763 million after tax.

While Tesla didn't receive any cash or sell any shares, the after-tax gain accounted for roughly 68.5% of the company's $1.114 billion GAAP net income. The revaluation of Tesla's SpaceX investment is one of the quarter's biggest contributors to the EV maker's bottom line.

Even though Tesla didn't sell a single SpaceX share or receive any cash from the investment.

SpaceX Bounty: Paper Gain, Not Cash Profit

The gain resulted from an increase in the estimated value of its SpaceX investment, which it purchased earlier this year for $2.002 billion. The company owns less than 1% of SpaceX and does not control the aerospace company.

Tesla recorded a pre-tax $1.005 billion gain on the investment. Because the gain was non-cash, the company removed it when reconciling net income to operating cash flow and also excluded it from its non-GAAP earnings presentation.

The numbers put the investment into perspective. The pre-tax paper gain alone was more than two-and-a-half times Tesla's operating profit (which was $398 million).

Tesla's automotive, energy storage and services businesses collectively produced just $398 million of operating profit, while the accounting gain on its SpaceX investment added more than $1 billion before taxes.

So, nearly 70% of Tesla's GAAP earnings came from a non-cash increase in the estimated value of its SpaceX stake—not from manufacturing or selling products.

Why Tesla's GAAP And Adjusted Earnings Tell Different Stories

The SpaceX gain was included in Tesla's official GAAP earnings under accounting rules governing equity investments, even though the company did not monetize its stake.

The SpaceX gain also helps explain why Tesla reported different GAAP and adjusted earnings.

Tesla reported GAAP net income of $1.114 billion, which included the after-tax SpaceX gain. It also reported non-GAAP net income of $1.153 billion, excluding the $763 million after-tax SpaceX gain along with several other items, including $989 million of stock-based compensation expense, an $87 million digital-asset loss and certain tax adjustments.

Although Tesla removed the $763 million after-tax SpaceX gain, it added back an even larger $989 million stock-based compensation expense, along with other adjustments, resulting in slightly higher adjusted earnings.

Why Investors Should Watch It

The disclosure doesn't mean Tesla's automotive business suddenly became less important, nor does it suggest the company generated an extra $763 million in cash.

Instead, it underscores how investments outside Tesla's core operations can materially influence reported earnings under GAAP accounting. If SpaceX's valuation continues to rise—or falls in future quarters—that stake could create meaningful swings in Tesla's reported profit even if vehicle deliveries, energy storage deployments and operating performance remain largely unchanged.

For investors, the quarter served as a reminder that one of the biggest drivers of Tesla's headline earnings wasn't what happened inside its factories. It was the changing value of a minority stake in another Elon Musk company.