AI, semiconductors, space, cybersecurity and defence are dominating thematic ETF demand among UK retail investors in 2026. Here Sharesify discusses the funds attracting the most attention.
Thematic ETFs have become an increasingly popular way for UK retail investors to target long-term investment trends without having to pick individual shares.
The standout theme in 2026 has been artificial intelligence and semiconductors. The VanEck Semiconductor UCITS ETF (LON:SMGB) ranked eighth in interactive investor’s August list of the most-bought ETFs overall, despite competing with broad-market giants such as Vanguard’s FTSE All-World and S&P 500 ETFs. SMGB delivered a rough 112% one-year total return to 31 August 2026.
Space is another rapidly emerging theme. VanEck Space Innovators (LON:JEDG) entered ii’s top 10 in May and remained there in June. The fund now has about £1.26bn of assets and charges a 0.55% annual expense ratio.
The 15 thematic ETFs attracting the most attention
| Rank | ETF | Theme | Approx. AUM | Annual fee | 1-year return* |
| 1 | VanEck Semiconductor (LON:SMGB) | Semiconductors/AI | $8.8bn | 0.35% | 112.1% |
| 2 | iShares MSCI Global Semiconductors (LON:SEMI) | Semiconductors/AI | $6.1bn | 0.35% | 186.8%† |
| 3 | VanEck Space Innovators (LON:JEDG) | Space | $1.7bn | 0.55% | 121.3%† |
| 4 | L&G Cyber Security (LON:ISPY) | Cybersecurity | ~£2.8bn | 0.69% | 40.7% |
| 5 | iShares Digital Security (LON:LOCK) | Cybersecurity | $1.9bn | 0.40% | ~25% |
| 6 | iShares Automation & Robotics (LON:RBOT) | Robotics/AI | ~£1bn+ | 0.40% | 35.1% |
| 7 | L&G ROBO Global Robotics (LON:ROBG) | Robotics/automation | ~£1bn+ | 0.80% | ~25% |
| 8 | iShares Global Clean Energy (LON:INRG) | Clean energy | £2.6bn | 0.65% | 23.5% |
| 9 | VanEck Uranium & Nuclear (LON:NUCL) | Nuclear/uranium | ~£1bn+ | 0.55% | 2.3% |
| 10 | HANetf Future of Defence (LON:NATP) | Defence/cybersecurity | ~€1bn+ | 0.49% | 15.9% |
| 11 | WisdomTree Cybersecurity (LON:WCBR) | Cybersecurity | ~€400m | 0.45% | 38.1% |
| 12 | L&G Battery Value-Chain (LON:BATT) | Batteries/EVs | ~€600m | 0.49% | ~32% |
| 13 | iShares Healthcare Innovation (LON:HEAL) | Healthcare/biotech | ~€1bn | 0.40% | – |
| 14 | VanEck Defense (LON:DFNS) | Defence | ~€6bn+ | 0.55% | — |
| 15 | VanEck Genomics & Healthcare Innovators (LON:CURE) | Genomics/biotech | smaller | 0.35% | — |
*Approximate ranking based on a blend of recent UK retail buying evidence, AUM, fund longevity, thematic relevance and performance. It is not an official industry ranking. Returns are latest available and are not necessarily measured on identical dates or in identical currencies. †Figures shown from the latest comparable ii data available rather than the current date.
Powerful semiconductors
The semiconductor numbers illustrate just how powerful the AI trade has become. iShares MSCI Global Semiconductors (LON:SEMI) had more than £4.36bn in assets by September and charges just 0.35%. Its June one-year return was 187%, marginally ahead of VanEck’s 176% at that point.
Cybersecurity is another major area of investor interest. L&G Cyber Security UCITS ETF (LON:ISPY) returned ~41% over the latest year available to 10 September, while iShares Digital Security (LON:LOCK) had almost £1.48bn in net assets and a 0.40% total expense ratio.
Robotics is benefiting from the same structural forces as AI. The iShares Automation & Robotics (LON:RBTX) returned ~35% over the latest year, with the fund also offering exposure to the industrial automation side of the AI investment cycle.
Top 5 thematic ETFs to watch
1. VanEck Semiconductor (LON:SMGB) £70.40
The clearest retail-investor AI ETF story. Its concentrated exposure to chipmakers gives investors a more direct way to target the infrastructure behind AI than a broad technology tracker. It was still one of ii’s 10 most-bought ETFs in August.
2. iShares MSCI Global Semiconductors (LON:SEMI) £14.36
A broader semiconductor approach than SMGB, with 259 holdings and £4.36bn in assets. It also charges just 0.35%.
3. VanEck Space Innovators (LON:JEDG) £57.75
One of 2026’s most interesting new retail themes. The fund targets companies generating revenue from satellites, launch systems, communications and other parts of the commercial space economy. But investors need to check what they’re buying. For example, the hugely volatile Rocket Lab (NASDASQ:RKLB) is in the ETF’s top 10 holdings, yet SpaceX (NASDAQ:SPCX) is not.
4. L&G Cyber Security (LON:ISPY) £35.56
Cybersecurity offers a particularly strong structural investment case as businesses increase spending to defend increasingly AI-enabled digital infrastructure. ISPY returned 40.7% over the latest year.
5. HANetf Future of Defence (LON:NATP) £15.69
Defence spending has become a major European investment theme. NATO returned 15.9% over the 12 months to July, with holdings spanning defence, aerospace and cybersecurity.
The bigger investment trend
The most important development is that the AI theme is spreading beyond the obvious technology giants.
Investors can now target different layers of the AI ecosystem: chips through semiconductor ETFs; physical infrastructure through energy and nuclear funds; automation through robotics ETFs; and protection of digital infrastructure through cybersecurity funds.
Space and defence add another dimension. Both are increasingly linked to satellite communications, autonomous systems, AI-enabled defence and advanced semiconductor technology.
Clean energy is a more controversial proposition. The iShares Global Clean Energy Transition UCITS ETF (LON:INRG) has recovered strongly over the past year, returning 23.5% in GBP, and has £2.2bn of assets. But its longer-term record demonstrates the risk of thematic investing: the fund suffered substantial losses in 2023 and 2024 before recovering in 2025 and 2026.
Nuclear is similarly a long-term rather than straightforward momentum trade. VanEck Uranium & Nuclear Technologies UCITS ETF (LON:NUCG) returned only about 2.3% over the latest year in the available data, despite delivering much stronger returns over three years.
Methodology: how we ranked the ETFs
There is no single database showing exactly what all UK retail investors own. This ranking therefore combines four factors:
Retail buying activity: interactive investor’s monthly most-bought ETF rankings, which provide the clearest publicly available evidence of UK retail behaviour.
Fund size: larger AUM generally indicates greater adoption and liquidity.
Thematic relevance: preference was given to genuine thematic funds rather than generic sector trackers.
Performance and cost: one-year returns and annual fees provide useful context but were not used alone to determine popularity.
Investors should also remember that thematic ETFs are usually more concentrated than global trackers. That can produce much higher returns when a theme is in favour — but also substantially larger losses when sentiment reverses.
Sharesify investor verdict
For UK retail investors, AI, semiconductors, space, cybersecurity and defence are dominating thematic ETF demand among UK retail investors in 2026.
The next phase of the market may be less about simply owning AI companies and more about owning the infrastructure required to build, power, automate and protect the AI economy.
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