Why UK Defence Stocks Are Rallying

The spending pledge behind the rally

The rally in UK defence stocks rests on a commitment with a number attached. At the 2025 NATO summit in The Hague, every member except Spain agreed to lift defence and security spending to 5 percent of GDP by 2035, split between 3.5 percent on core military capability and 1.5 percent on wider security. That pledge was reaffirmed at the alliance's Ankara summit in July 2026, and progress is due for formal review in 2029. For companies that build ships, aircraft, munitions and the systems that connect them, a decade-long ramp in government budgets is about as clear a demand signal as the market offers. It is the reason a sector that spent years out of fashion has become one of the strongest performers on the London market.

Why it matters right now

The spending is not a forecast. It is already landing. Global military expenditure reached a record $2.89trn in 2025, according to the Stockholm International Peace Research Institute, an eleventh consecutive year of growth that lifted the world's military burden to 2.5 percent of GDP, its highest share since 2009. Europe drove the increase, with spending up 14 percent to $864bn, the fastest annual rise among NATO's European members since 1953. Germany alone raised its budget by 24 percent to $114bn, crossing 2 percent of GDP for the first time since 1990 and pledging to reach 3.5 percent by 2029. The United States remained comfortably the largest spender, and Congress has approved more than $1trn for 2026.

For a UK investor, this backdrop reaches the London market directly, and it has put UK defence stocks back on retail radars after years of neglect. Defence primes work on multi-year, government-backed contracts, which turn political commitments into visible, contracted revenue. Order backlogs at the largest names now stretch years into the future, giving a kind of earnings visibility that most industrial businesses can only envy. That visibility, more than any single quarter's results, is what has repriced the sector.

What puts a stock in the UK defence basket

Openbook does not label a company a defence stock on the strength of a headline. Each business is scored against the same factor model, and the theme is defined by the profile that model surfaces. The clear anchor of the UK sector is BAE Systems, the largest pure-play UK defence company by both market capitalisation and revenue, with a record order backlog and a dividend it has raised every year since 2003. On the Reward side, names like this tend to score well on Growth, because contracted backlogs feed steady revenue expansion, and on Momentum, because the shares have trended strongly as budgets have risen. Profitability is usually solid, supported by long programmes and improving margins, which is the kind of pattern that can earn a Quality Compounder tag or, on the income measures, a Dividend King one.

One important distinction the model helps make is between a pure defence play and a diversified industrial with defence exposure. Rolls-Royce carries a larger market capitalisation than BAE Systems, but it draws most of its revenue from civil aerospace, with defence contributing under a quarter of the total, alongside a growing power systems and small modular reactor business. It qualifies for exposure to rising defence budgets, but it is not a pure-play, and its share price responds to air travel and power demand as much as to military spending — our Rolls-Royce share price analysis works through that split in detail. The factor most likely to flash amber across the sector now is Valuation, which carries the smallest Reward weight at fifteen percent. After a strong rerating, several of these shares trade at rich multiples, so a high overall Reward Score can sit beside a weak Valuation read. Beyond BAE Systems and Rolls-Royce, the sector runs deep, taking in names like Babcock International in naval support, QinetiQ in defence technology and Chemring in countermeasures, each scored on the same factors rather than grouped together by label. You can filter the whole market on those measures through the Openbook stock screener.

How to weigh the risks

Compared with the more speculative themes on the platform, defence sits at the lower, steadier end of the risk range, and the factor scores usually show it. On the Openbook Risk Score, defence primes tend to post strong Financial Solvency, the second heaviest risk factor, along with lower Volatility than momentum-driven sectors and the reassurance of large size and deep liquidity. Long government contracts and contracted backlogs give these businesses a stability that most cyclical industrials lack.

That does not make the theme risk-free. Spending pledges run to 2035, and a decade is long enough for governments and priorities to change. Researchers have already flagged the risk of creative accounting as countries stretch the definition of security spending to hit their targets, which means headline commitments and actual orders can diverge. A meaningful easing of geopolitical tension could soften sentiment quickly, even if contracted work continues. Programme execution is its own risk, since large defence projects run late and over budget often enough to matter. Valuations, having already rerated, leave less room for error than they did two years ago, and that is most true of the names trading at the highest multiples. There is also an investor base consideration: some funds and individuals exclude defence on ethical grounds, which can narrow the pool of buyers for these shares. None of this offsets the strength of the demand backdrop, but it is the difference between low to moderate risk and no risk at all.

See the scored list

The demand story for defence is easy to state and harder to translate into which specific companies are worth watching and on what terms. That is where a single consistent scoring model helps. See the live, scored list of UK defence stocks, each rated on the same Reward and Risk factors, on the Openbook Discover page. It is the quickest way to move from the macro picture to the individual companies that currently qualify under Openbook's criteria, with their growth, momentum, profitability and risk reads laid out side by side so you can judge them on the same terms rather than on the loudest headline.

Openbook is an educational research platform. We do not give personalised recommendations or investment advice.