Rolls-Royce SpaceX Share Price Compared: What the Numbers Actually Show

The Rolls-Royce SpaceX share price debate has sharpened considerably in recent months, with Rolls-Royce Holdings (LSE: RR.) posting its ninth earnings upgrade in just over two years, while Space Exploration Technologies (Nasdaq: SPCX) completed what became the largest IPO in history. Both stocks have generated serious investor interest. The underlying investment cases, however, could hardly be more different.

Rolls-Royce: earnings momentum meets balance-sheet ambition

Rolls-Royce’s 2025 full-year results were unambiguous. Underlying operating profit reached £3,462 million, with an underlying operating margin of 17.3% and free cash flow of £3,270 million. All three divisions contributed. Civil aerospace revenue grew 15% to £10.38bn; the defence business generated £4.77bn, up 8%; and power systems added £4.89bn, up 19% year-on-year.

Management used those results to upgrade the mid-term financial targets substantially. The prior guidance of £3.6bn–£3.9bn underlying operating profit and £4.2bn–£4.5bn free cash flow was replaced with new targets of £4.9bn–£5.2bn in underlying operating profit and £5.0bn–£5.3bn in free cash flow for the medium term. Alongside that, the company announced a £7bn–£9bn multi-year share buyback programme for 2026–2028, with £2.5bn to be returned to shareholders in 2026 alone.

For income-focused investors, the 2025 total dividend of 9.5p per share was 58% higher than the prior year. Basic earnings per share came in at 29.55p, up 46%. The earnings cadence here is a long way from speculative.

There is a longer-term optionality case in Rolls-Royce’s small modular reactor programme. Following its November 2024 trading update, Rolls-Royce SMR was named preferred supplier by the Czech Republic and state utility ČEZ Group, with an exclusive commitment to deploy up to 3GW of electricity. In the UK, it remains the only company at Step 3 of the Generic Design Assessment, approximately 18 months ahead of competing entrants. How much of that is already embedded in the share price is a fair question, and one the market will keep asking.

SpaceX: scale, losses, and the Starlink growth engine

SpaceX’s IPO, priced at $135 per share with an initial offering of 555.56 million shares raising $75 billion, valued the company at $1.77 trillion based on 13.08 billion shares outstanding. Underwriters subsequently exercised their green-shoe option, purchasing an additional 83.3 million shares and bringing total proceeds to $85.7 billion. The stock opened Nasdaq trading at $150 and closed its first full day up 7.5%, after surging 19% at its debut, with first-day closing valuation exceeding $2 trillion. IPO demand exceeded $350 billion in aggregate.

The financials disclosed in the S-1 filing tell a more complicated story. SpaceX recorded a net loss of $4.9 billion in 2025 on consolidated revenue of $18 billion, with EBITDA of $6.58 billion. The AI segment alone carried a $6.35 billion operating loss. Approximately $20 billion of IPO proceeds are earmarked to extinguish debt tied to legacy loans from X and xAI, both folded into SpaceX before listing.

Starlink remains the engine worth watching. Subscribers reached 12.0 million as of 30 June 2026, double the 6.0 million recorded a year earlier, across 167 countries with 10,200 satellites in orbit. Starlink’s connectivity adjusted EBITDA for the second quarter of 2026 was $2.60 billion. The growth is real. The pressure on average revenue per user is also real: ARPU fell from $85 to $66 per month over the same period, a 22% decline, reflecting competitive pricing as the service scales.

Capital expenditure is the figure that gives investors pause. Q2 2026 capex reached $18.369 billion, comprising $15.828 billion directed to AI, $1.367 billion to connectivity, and $1.174 billion to the space segment. First-half 2026 capex totalled $28.476 billion. A JPMorgan analyst projected capex approaching $200 billion in both 2027 and 2028, even as management suggested annual revenue run rate could reach $100 billion by year-end. That gap between capital consumption and revenue generation is the central risk.

Which Rolls-Royce SpaceX share price scenario is more plausible?

ChatGPT, when posed the doubling question in the original analysis that prompted this piece, hedged sensibly: it picked Rolls-Royce over three to five years and SpaceX over two, noting the latter ‘would imply an extraordinarily large company valuation.’ The framing is reasonable, if unverifiable.

The more grounded observation is this: Rolls-Royce has the earnings trajectory, the buyback programme, and the upgraded targets to support a valuation re-rating on conventional metrics. SpaceX is a bet on Starlink’s subscriber trajectory continuing, Starship commercialisation, and the AI segment eventually turning profitable despite absorbing the majority of an enormous capex budget. Both bets may pay off. The Rolls-Royce case rests on execution of a visible plan; the SpaceX case rests on a growth narrative that the capital expenditure figures will need to validate, and quickly.

The next material test for Rolls-Royce is whether 2026 free cash flow tracks toward the £5.0bn–£5.3bn mid-term target. For SpaceX, it is whether Starlink ARPU stabilises as subscriber growth continues, and whether the AI segment narrows its losses before the IPO proceeds are absorbed.