Three UK Growth Shares (CMCX, HDD, KLR) That Are Quietly Outpacing The S&P 500 In 2026

While US markets dominate conversations about growth investing, the S&P 500 has only managed a roughly 10% gain so far in 2026.

The tech-heavy index is packed with bloated megacaps carrying high valuations, leaving many investors searching for better opportunities elsewhere.

Back home, the FTSE 100 has long been associated with high-yielding dividend stocks, reflecting the income-focused preferences of traditional UK investors.

That reputation can make UK shares feel uninspiring, but for investors willing to dig deeper, genuine growth opportunities are hiding in plain sight.

Three London-listed stocks have quietly delivered returns that put the S&P 500 to shame this year, spanning trading platforms, specialist coatings, and ground engineering.

CMC Markets (LSE: CMCX) is a multi-asset online trading and investing platform that turned a strong year of market volatility into record financial results.

FY2026 results revealed net operating income up 15% to £392.6m, while profit before tax climbed 20% to £101.3m, reflecting the platform’s ability to capitalise on heightened trading activity.

Management is aggressively pursuing institutional and B2B partnerships, Australian stockbroking alliances, and API deals with online banks, alongside plans for a UK “Super App.”

Return on equity sits at around 17%, suggesting the business is deploying shareholder capital efficiently, though rising operating expenses during this investment phase introduce meaningful execution risk.

For investors bullish on the growth of retail and gamified trading, CMC Markets represents a compelling, if not straightforward, opportunity worth serious consideration.

Hardide (LSE: HDD) is an AIM-listed penny stock providing specialist industrial coatings, with shares hovering around 70p to 80p and a market capitalisation close to £57.5m.

For the year to 30 September 2025, revenue increased 27% to £6m and EBITDA reached £1m, moving the business firmly into profitable territory for the first time.

Return on equity looks high at 33%, though this partly reflects a modest equity base rather than purely exceptional operational performance.

Management is focused on aerospace and energy customers, with growth plans centred on North America, which is an attractive angle but one that also exposes the business to customer concentration risk.

Valuation is where investors need to exercise caution, with a price-to-book ratio of 7.78, far above many industrial peers and consistent with a highly speculative price tag.

Keller Group (LSE: KLR) is a global ground-engineering contractor with a solid foundation in infrastructure and construction, offering a steadier growth narrative than many hyped US tech stories.

The group’s 2025 annual report described “record financial performance”, with revenue up 3% to £3,087.3m and underlying operating profit up 2.6% to £218.2m, representing a 7.1% margin.

A return on equity of around 23% suggests Keller is managing shareholder capital with real discipline, while the group finished 2025 in a net cash position of £59.7m.

Keller also holds a £1.5bn order book and has announced plans for a £100m share buyback, signalling strong management confidence in the business going forward.

CEO James Wroath described 2025 as “a time of such strong performance and clear opportunity,” reinforcing the sense that the group is operating from a position of genuine momentum.

Construction and infrastructure remain cyclical sectors, meaning Keller’s fortunes will be partly tied to broader economic conditions and any potential softening in global project pipelines.

Nevertheless, with a combination of decent growth potential, a sensible valuation, and a long-term compounding track record, Keller Group stands out as a strong contender for patient investors with a 10 to 20-year horizon.