Rolls-Royce vs SpaceX Stock Comparison: Which Aerospace Play Fits a Long Portfolio?

The Rolls-Royce vs SpaceX stock comparison has sharpened considerably since SpaceX (SPCX) completed the largest IPO in history in June 2026, raising $75bn and eclipsing the $35.4bn record Saudi Aramco set in 2019. Two aerospace heavyweights, one with a century of engineering heritage and one still posting nine-figure losses, now sit in the same conversation for UK investors building long-term positions.

Two Very Different Balance Sheets

Rolls-Royce (RR.) reported 2025 revenue of £20.06bn, underlying operating profit of £3.46bn (up 38% on an organic basis), and free cash flow of £3.27bn, which was £845m higher than the prior year. Basic EPS rose 46% to 29.55p. Net cash stood at £1.9bn, the company resumed dividends at 9.5p per share, and management announced a £7bn to £9bn share buyback programme running from 2026 to 2028, with £2.5bn earmarked for completion in 2026 alone.

The civil aerospace division, Rolls-Royce’s largest revenue segment, grew 15% to £10.38bn in 2025. The group’s underlying operating margin reached 17.3%, up from 13.8% in 2024, with civil aerospace posting a 20.5% margin as large-engine flying hours rose 8% year on year.

SpaceX’s finances tell a different story. The company posted 2025 revenue of $18.674bn alongside a net loss of $4.937bn. Within that, Starlink generated $11.387bn in revenue and $4.423bn in operating profit on roughly 10.3 million subscribers, but the xAI division ran an operating loss of $6.355bn, effectively consuming Starlink’s gains and then some.

Rolls-Royce vs SpaceX: How the IPO Reshaped the Conversation

SpaceX’s Class A Common Stock (par value $0.001), listed on Nasdaq under the ticker SPCX, opened at $150 on its 12 June debut before closing at $160.95, a 19.2% first-day gain. At that close, Bespoke Investment Group noted that SpaceX was ‘the sixth largest US company behind Amazon at $2.54 trillion and ahead of Broadcom (AVGO) at $1.81 trillion’ and that ‘Elon Musk’s SPCX is already $700 billion larger than Tesla (TSLA), and it’s more than twice the size of Berkshire Hathaway (BRK-B).’ Wedbush analyst Dan Ives described the listing as ‘an important moment for the broader tech sector’ and framed it within ‘this AI Revolution.’

The stock retreated from those highs and by mid-July had dipped below its $135 IPO price at times, hovering around the mid-$130s. SpaceX was added to the Nasdaq-100 within approximately one month of listing after Nasdaq revised its rules to permit inclusion that quickly for new public companies, which provided a mechanical bid from index-tracking funds.

The valuation debate is unresolved. Some fair-value estimates sit closer to $780bn, less than half the mid-July market price. The SpaceX 8-K filed 4 August 2026 and the Q2 2026 10-Q confirm the company reports across three segments: Space (launch services), Connectivity (Starlink consumer and enterprise) and AI. Execution risk spans all three, and the xAI losses make it difficult to model a near-term path to group profitability.

Where Rolls-Royce Goes From Here

Management guided 2026 underlying operating profit of £4bn to £4.2bn and free cash flow of £3.6bn to £3.8bn. The upgraded mid-term targets are more ambitious still: £4.9bn to £5.2bn in operating profit and £5.0bn to £5.3bn in free cash flow, raised from previous targets of £3.6bn to £3.9bn and £4.2bn to £4.5bn respectively.

Shares traded around 1,373p in mid-July, giving a market cap of roughly £113.6bn. Analyst consensus as of 30 July 2026 stood at 3 Buy, 13 Outperform, 2 Hold and 1 Sell, with a median price target of 1,575p implying 7.3% upside and a high target of around 1,870p. The risks are real: civil aerospace earnings remain tied to long-haul flying hours, and a material slowdown in air travel would pressure the engine-services revenue line. Defence and power systems offer partial insulation but do not eliminate cyclical exposure.

For a long-term portfolio, the contrast resolves fairly cleanly. Rolls-Royce is generating cash, returning capital and guiding higher; the thesis rests on margin delivery and flying-hour recovery, both of which are measurable. SpaceX is priced for a decade of rapid expansion that has yet to show up at the group net-income line. The next test for both comes with Rolls-Royce’s half-year results and SpaceX’s Q3 2026 filing, where Starlink subscriber growth and xAI cost trajectory will either justify or further strain the current multiple.