Elon Musk’s proposed merger between Tesla and SpaceX could give the privately held space company a new route into the S&P 500, potentially unlocking billions of dollars in investment from funds tracking the benchmark index. The proposed combination would bring together two of the world’s most valuable businesses, spanning electric vehicles, artificial intelligence, robotics, satellite communications and aerospace.
The possibility has gained attention after SpaceX failed to secure a fast-track entry into the S&P 500 following its public listing. A merger with Tesla, which is already a constituent of the benchmark, could create a different route for the combined company to retain or secure index membership. According to Bloomberg, the transaction could generate approximately $100 billion in buying demand from passive investment funds, although inclusion is not guaranteed and the merger itself remains under discussion.
How a Tesla-SpaceX Merger Could Help SpaceX Enter the S&P 500
The S&P 500 is one of the world’s most widely followed stock market indices. It tracks 500 leading publicly traded US companies and serves as a benchmark for a large number of investment funds and exchange-traded funds.
Tesla is already part of the index, meaning funds tracking the benchmark hold its shares according to the company’s index weighting.
SpaceX, despite its enormous market valuation and public listing, faced a different challenge. S&P Dow Jones Indices did not change its rules to accommodate large newly listed companies seeking rapid entry into the benchmark.
A merger with Tesla could create an alternative route.
If the transaction is structured so that the combined company succeeds Tesla as the existing index constituent, it could potentially preserve the company’s place in the S&P 500. However, the index provider would still have to determine whether the resulting company satisfies its eligibility and index-maintenance requirements.
The structure of the transaction will therefore be important.
The easiest theoretical route would be for Tesla to acquire SpaceX, allowing the combined entity to retain Tesla’s existing index position. However, analysts have suggested that this is not necessarily the most likely transaction structure.
Another possibility is that SpaceX acquires Tesla, with the combined company seeking to retain Tesla’s position in the benchmark.
Neither outcome has been confirmed.
Potential $100 Billion Demand From Passive Investment Funds
One of the biggest financial implications of the proposed merger is the potential demand from index-tracking funds.
According to Bloomberg, Reid Noch of TD Securities estimates that the inclusion of the combined company could generate approximately $100 billion in buying demand from passive investment funds.
These funds track indices such as the S&P 500 and are required to hold constituent stocks in proportions determined by their index weightings.
When a company enters a major benchmark, funds tracking that index typically purchase shares to reflect the new composition. This can create substantial demand, particularly when the company has a large market capitalisation.
The potential impact is significant because Tesla and SpaceX together had a combined market value of nearly $3.5 trillion based on the prices cited in Bloomberg’s November 14 report.
That would make the combined business approximately the fifth-largest company in the S&P 500 by market value.
However, the estimated $100 billion represents potential index-related buying demand, not guaranteed new investment into the companies. Actual purchases would depend on the transaction structure, index-provider decisions and the final weighting of the combined business.
Why SpaceX Previously Faced an S&P 500 Entry Challenge
SpaceX’s route into the S&P 500 has been complicated by the index’s eligibility requirements.
Among the key requirements are a minimum period of public trading and profitability over the most recent four consecutive quarters.
A company generally needs to have traded publicly for at least 12 months and report positive earnings under the index’s criteria.
SpaceX did not initially satisfy all the requirements for inclusion following its public listing.
Bloomberg reported that, based on analyst estimates available at the time, SpaceX could meet the profitability requirement by the middle of 2027.
The company had also received a different treatment from Nasdaq.
Following SpaceX’s record-setting public listing in June 2026, Nasdaq changed its rules to accelerate the company’s potential inclusion in the Nasdaq-100 Index, which is tracked by approximately $800 billion in assets.
S&P Dow Jones Indices, however, did not make a similar change to accommodate large newly listed companies.
A merger with Tesla could therefore provide a separate opportunity to address the index-membership issue without requiring the S&P 500 to change its general IPO eligibility rules.
Musk’s Proposed Merger Would Combine AI, Robotics and Space Businesses
The potential transaction is not solely about index inclusion.
Musk has argued that combining Tesla and SpaceX could create operational advantages by bringing their technology and investment plans under one corporate structure.
Tesla operates in electric vehicles, battery storage, autonomous driving and robotics. SpaceX operates rocket launch services and Starlink satellite internet, while also investing heavily in artificial intelligence and space-based infrastructure.
Both companies have overlapping ambitions in areas such as AI computing, autonomous systems and advanced manufacturing.
Musk publicly supported exploring a merger during SpaceX’s third-quarter earnings call in October 2026. He confirmed that the companies had established special committees of independent directors to examine a possible combination.
He also said he was not participating in those committee discussions because of his position as a conflicted party.
No final terms have been agreed, and Musk has cautioned that a merger is not certain.
Reuters reported on November 12 that discussions between the companies were progressing, with an announcement potentially possible as early as December 2026. An alternative timeline could push any announcement into early 2027.
Combined Company Could Be Valued at Nearly $3.5 Trillion
The scale of the proposed combination would be substantial.
| Company or metric | Reported figure |
|---|---|
| Tesla market value | Approximately $1.55 trillion |
| SpaceX market value | Approximately $1.90 trillion |
| Combined market value | Nearly $3.5 trillion |
| Potential S&P 500 fund demand | Approximately $100 billion |
| Estimated combined S&P 500 ranking | Fifth largest |
These figures reflect market valuations cited in recent reporting and can change with share prices.
A combined company would bring together businesses with different revenue models, investment requirements and operating risks.
Tesla’s performance is influenced by vehicle demand, battery production, autonomous driving and energy storage. SpaceX’s businesses depend on launch services, satellite connectivity, government contracts and the development of new space technologies.
The combination could create opportunities to share technology and infrastructure, but it would also place a wide range of businesses under one corporate structure.
Merger Faces Governance and Regulatory Challenges
Despite the potential benefits, the transaction could face substantial obstacles.
One major issue is corporate governance.
Musk leads both companies, creating questions about how the interests of shareholders in each business would be protected during negotiations.
Independent director committees have been formed to examine the proposal, but the final transaction would still require appropriate approvals.
Tesla shareholders would also play a central role. Musk has previously indicated that approval would require support from 50% of all shares, rather than simply a majority of shareholders who vote.
Regulatory scrutiny could be another challenge.
SpaceX has significant US government and defence-related contracts, while Tesla has extensive manufacturing and commercial relationships in China. Combining the businesses could raise questions involving national security, foreign business exposure, competition and government procurement.
The companies would also need to determine an appropriate valuation and exchange ratio for shareholders.
No final transaction terms or completion timeline have been announced.
S&P 500 Inclusion Could Increase Market Concentration
A combined Tesla-SpaceX company could become one of the largest constituents of the S&P 500.
That would have consequences beyond the two companies.
The S&P 500 already has substantial exposure to large technology and AI-related businesses. Adding another company with a potential market value of nearly $3.5 trillion could increase the influence of a small group of mega-cap stocks on the overall benchmark.
Investors holding index funds would gain exposure to the combined company even if they had not specifically chosen to invest in Musk’s businesses.
Market concentration is therefore an important concern.
Bloomberg quoted market analysts warning that the growing weight of AI-related companies in major indices could make benchmark performance increasingly dependent on a relatively small number of businesses.
The potential addition of companies such as Anthropic and OpenAI through future public listings could further change the composition of major US equity benchmarks.
The Bigger Picture
The proposed Tesla-SpaceX merger highlights how corporate combinations can have consequences beyond traditional business synergies.
For Musk, combining the companies could bring together investments in artificial intelligence, robotics, energy, satellite networks and space technology. It could also create a potential route for SpaceX to benefit from Tesla’s existing position in the S&P 500.
For investors, the most significant question is whether the combined company would qualify for index membership and how much influence it would have on the benchmark.
The estimated $100 billion in potential passive-fund demand illustrates the financial importance of index inclusion. However, the figure remains an estimate, and the transaction would not automatically guarantee S&P 500 membership.
The proposal also raises broader questions about market concentration, corporate governance and the growing influence of large technology companies in investment portfolios.
Looking Ahead
The next major developments will depend on the independent committees’ discussions, the structure of any proposed transaction and the approval process involving shareholders and regulators. Reports suggest that an announcement could come as early as December 2026, although negotiations could extend into early 2027. Until the companies disclose formal terms, the merger remains a proposal rather than a completed transaction.
If the deal proceeds, S&P Dow Jones Indices will face questions about how the combined company should be treated under its existing membership rules. Potential inclusion could generate substantial buying demand from passive investment funds, but it is not guaranteed. The outcome will depend on the final corporate structure, eligibility requirements and the index provider’s decision.
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