Levine, Prinz Magtulis, Abhirup Roy, Anhata Rooprai, Sumanta Sen, Akash Sriram Elon Musk said on Tuesday that a merger of his two companies, SpaceX and Tesla, would be “a good idea” and that they had formed special committees to discuss a union.

Top 10 public companies in the U.S., by market capitalization Before a merger After a merger Nvidia Apple Alphabet Microsoft $3.5 trillion Amazon SpaceX & Tesla Projected if merger proceeds $2.0 trillion SpaceX Meta Platforms Broadcom Berkshire Hathaway Tesla Eli Lilly Bar charts rank the 10 largest US public companies by market value. SpaceX ($2.0 trillion) is sixth and Tesla ($1.5 trillion) ninth. Combined, at $3.5 trillion, they would rank fifth, behind Nvidia, Apple, Alphabet and Microsoft, ahead of Amazon.

Source: LSEG Tesla is an established carmaker trying to reinvent itself around AI and robotics. It has the steadier business, but costs are rising and heavy investments are expected to prove its robotaxis and robotics bets will pay off.

SpaceX is growing faster and has posted its first profit as a public company in the third quarter, driven by AI and Starlink. It is spending heavily to keep that growth going, which leaves it dependent on fresh funding. Below are key financial metrics for the two Elon Musk-led companies.

Tesla shares rose 3.4% on Wednesday to close at $386.47. That gave it a market value of about $1.53 trillion. The move followed Musk’s comment that a merger of SpaceX and Tesla would be “a good idea”. SpaceX listed in June with an issue price of $135 a share, raising $86 billion, the largest public offering ever.

Its shares jumped 7.8% on Wednesday to $159.31 on the merger comment and its first profit as a public company. That lifted its market value to about $2.16 trillion.

Tesla’s revenue for the first nine months of 2026 rose to $78.67 billion from $69.93 billion a year earlier, as its EV sales recovered amid high gasoline prices and subscriptions to its Full Self-Driving software grew.

SpaceX’s revenue for the first nine months of 2026 nearly doubled to $27.08 billion from $13.7 billion, driven by continued growth in its Starlink and AI businesses.

Investors are paying about $12.50 for every $1 of Tesla’s sales estimated over the next 12 months. That compares with about $14.50 for SpaceX.

Tesla posted a $4.3 billion profit for the first nine months of 2026, helped by a recovery in its EV sales and growth in its high-margin FSD software subscriptions, as well as EV charging and insurance.

SpaceX had a loss of $413 million during the same period, as it continued to spend heavily on AI infrastructure. Its losses nevertheless narrowed from the first ninth months of 2025 thanks to its new, high-margin data center business. In the third quarter, the company swung to a profit of $4.4 billion for the first time as a public company.

Tesla’s debt stood at $9.5 billion as of September 30. About $6 billion of that is a loan in China that funds day-to-day operations. Tesla has also arranged $30 billion in new credit lines, but it hasn’t used any of that money and says it doesn’t plan to this year.

SpaceX’s debt was $38.8 billion at the end of September. Of that, $25 billion was senior unsecured notes it sold in June. They mature between 2031 and 2056. On Sunday, Musk said SpaceX had closed $40 billion in debt financing for graphics processing units.

Tesla cut its 2026 capital spending forecast to about $20 billion from more than $25 billion. Capex in the first nine months of 2026 stood at $13.01 billion. That included $4.7 billion in the third quarter, well below analysts’ expectations of $7.5 billion.

SpaceX spent $48.1 billion over the same nine months. That included $19.6 billion in the third quarter, mainly on AI compute, Starship infrastructure and satellite production. It expects capital spending to accelerate further to between $35 billion and $40 billion in the fourth quarter.

Tesla generated $1.88 billion more cash than it spent in the first nine months of 2026, helped by capital spending that came in well below expectations.

SpaceX is still spending far more than it brings in. It burned $34.97 billion in cash during the same nine-month period. Analysts expect its free cash flow to remain negative in the fourth quarter.

A combination with Tesla could ease some of the pressure on SpaceX’s free cash flow by allowing the companies to share services and borrow jointly, say analysts.

Tesla ended September with $45.4 billion in cash and investments - about $1.4 billion more than what it had at the beginning of 2026. It also invested $2 billion in SpaceX stock during the first nine months, a financial tie between the two companies.

SpaceX’s ended September with $51.3 billion in cash, after its stock market debut in June brought in $85.7 billion.

While there is no deal yet, a Tesla-SpaceX combination would dwarf the biggest mergers of the past decade in terms of the companies’ combined market value.

Largest mergers and acquisitions of the last decade Deal value Tesla - SpaceX Activision Blizzard - Microsoft Time Warner - AT&T VMware - Broadcom 21st Century Fox - Walt Disney Raytheon - United Technologies Allergan - Abbvie Celgene Corp. - Bristol-Myers Squibb Shire - Takeda Pharmaceutical Express Scripts - Cigna Warner Brothers Discovery - Paramount Market capitalization on the day merger was announced Bar chart of the biggest mergers of the last decade by combined market value on announcement day. Tesla and SpaceX would top the list, ahead of Microsoft and Activision Blizzard. The rest were far smaller.

Note: Mergers and acquisitions among companies with the same owners or internal reorganisations have not been considered Valuation is likely to be the next battleground. Tesla shareholders would be swapping stakes in an independent company, where Musk holds about 20% of the voting power, for shares in SpaceX that Musk controls. Analysts have said a merger would give him control of the combined entity.

Sources LSEG; Company financial statements Edited by Rebecca Pazos, Julia Wolfe, Soyoung Kim and Sonali Paul