UK smaller companies have had a rough few years. Persistent outflows from the sector, higher interest rates, and a general preference among investors for large, liquid, dollar-earning stocks left many small-cap shares trading well below what their underlying businesses were arguably worth. That's now starting to shift, with falling interest rates, a pickup in takeover activity, and renewed manager conviction all pointing in the same direction.

This guide explains what a small-cap fund actually is, why the timing argument for the sector has changed, which UK small-cap investment trusts and open-ended funds have performed best, and — because the two structures work quite differently for this particular asset class — how to decide which is the better fit for you.

What is a small-cap fund?

small cap fundA invests in the shares of smaller listed companies. In the UK, "small-cap" generally means companies outside the FTSE 100 and FTSE 250 — roughly, constituents of the FTSE Small Cap Index and many AIM-listed companies. There's no single official cut-off, but as a rough guide, small-caps typically sit below £500 million–£1 billion in market value, while "micro-caps" — an even smaller sub-category some specialist funds target — are often defined as companies under £250 million.

Small-cap funds come in two structurally different forms:

Open-ended fundsUK Smaller Companies (unit trusts and OEICs), which sit in the Investment Association's (IA) sector, deal daily at net asset value (NAV), and create or cancel units to match investor demand.
Closed-ended investment trustsUK Smaller Companies, which sit in the Association of Investment Companies' (AIC) sector, have a fixed pool of shares that trade on the stock exchange and can move to a discount or premium versus NAV.

Both give you diversified exposure to smaller UK companies, but the structural difference matters more here than in most other sectors — more on that below.

Why invest in UK small-caps now?

Three factors are currently driving renewed interest in the sector:

The interest rate backdrop has turned. Smaller companies, as a longer-duration, more domestically exposed asset class, have historically struggled when interest rates rise and tended to recover as rates fall. With the Bank of England having lowered its base rate, the historical tailwind for small-caps is arguably back in play.
Valuations reflect years of outflows, not necessarily fundamentals. Persistent selling pressure from investors exiting UK equity funds broadly has left many smaller companies trading on valuations well below their long-term averages, even where underlying trading has held up.
Takeover activity has picked up. Depressed valuations have made UK small-caps attractive to trade buyers and private equity. Several small-cap fund managers have highlighted rising bid activity among their portfolio companies during 2026 as evidence that "smart money" sees value the wider market hasn't yet priced in.

None of this guarantees a recovery on any particular timeline — small-caps are, by their nature, a higher-risk, higher-volatility part of the market, and past underperformance is not evidence that a rebound is imminent.

Top-performing UK small-cap investment trusts

Within the AIC's UK Smaller Companies sector, performance leadership has been fairly consistent at the top, though the sector's line-up changed materially in April 2026 when two of its members merged.

Trust	Style	10-yr share price total return*	Discount/Premium*
Rockwood Strategic (RKW)	Value, concentrated (sub-£250m companies)	393%	+3% (premium)
JPMorgan UK Smaller Companies Growth & Income (JUGI)	Quality/growth	196%	-4.3%
BlackRock Smaller Companies (BRSC)	Growth (post-merger with Throgmorton)	156%**	-9.4%**
Rights & Issues Investment Trust	Concentrated, value	146%	-15.6%
Aberforth Smaller Companies (ASL)	Value	130%	-8.9%

*Figures are illustrative, drawn from data reported in early 2026, and change frequently — always check a live source such as theaic.co.uk before investing. **Historic figure relates to BlackRock Throgmorton, which merged into the enlarged BlackRock Smaller Companies Trust in April 2026; Throgmorton's former manager, Dan Whitestone, now co-manages the combined ~£780 million trust alongside BRSC's Roland Arnold.

Sharesify Strategic has consistently ranked as the AIC UK Smaller Companies sector's strongest performer over three and five years, run by Richard Staveley with a value-investing, engagement-led approach focused on companies below £250 million. Its most recent full-year results (to 31 March 2026) showed NAV total return of 7.1% and NAV growth from £96.6 million to £149.4 million, aided by a 44.5% increase in shares in issue amid strong investor demand; by mid-2026 NAV total return had risen a further 17% on the back of takeover approaches for portfolio holdings.

Aberforth Smaller CompaniesBlackRock Smaller Companiesgrowth-focused remains the largest individual trust in the sector at roughly £1.3 billion, following a disciplined value approach, while the newly enlarged is now the largest trust in the sector following its combination with Throgmorton.

Top-performing UK small-cap open-ended funds

In the IA UK Smaller Companies sector, two funds have consistently led on longer-term performance, though the sector as a whole has trailed the broader UK market over the past five years:

Fund	Style	Approximate 5-yr return*
Fidelity UK Smaller Companies	Value/recovery-focused	Sector-leading 5-year return, roughly 55–100%+ depending on measurement date
Aberforth UK Small Companies	Value	First-quartile over 1, 3 and 5 years
Schroder UK Smaller Companies	Value, managed by Andy Brough	Leading 3-year performer in the sector
Unicorn UK Smaller Companies	Growth-quality	Consistently competitive across time frames
WS Gresham House UK Micro Cap	Dedicated micro-cap	Focused on the smallest end of the listed market

*Performance figures for open-ended funds vary meaningfully depending on the exact measurement date and data provider — the ranges above reflect the spread seen across sources during 2026, not a single definitive number. Check a live factsheet (e.g. via Trustnet or the fund provider) before making any decision.

Fidelity UK Smaller CompaniesAberforth UK Small Companies, managed by Jonathan Winton, focuses on undervalued companies whose recovery potential the wider market hasn't yet recognised, and has posted the strongest five-year return in its IA sector on several recent measurement dates. applies a similarly disciplined value approach and has ranked in the first quartile of its sector across multiple time periods.

Investment trust or open-ended fund: which suits small-caps better?

This is one sector where the structural difference between trusts and open-ended funds genuinely changes the risk profile, not just the mechanics:

Factor	Investment trust	Open-ended fund
Dealing price	Share price can trade at a discount or premium to NAV	Always trades at NAV
Forced selling risk	None — closed-ended structure means the manager isn't forced to sell holdings to meet redemptions	Can be forced to sell less-liquid small-cap holdings during heavy redemption periods, potentially at unfavourable prices
Gearing	Can borrow to invest more than 100% of capital, amplifying gains and losses	Generally cannot gear in the same way
Income smoothing	Can retain up to 15% of income annually to smooth dividends	Must generally distribute income as received
Price transparency	Requires checking both share price and NAV/discount	Single NAV price, simpler to track

In practice: because small and micro-cap shares are inherently less liquid, the closed-ended structure's protection against forced selling is a genuine, structural advantage for this specific asset class — it's part of why several of the AIC sector's specialists (Rockwood Strategic among them) argue the trust wrapper suits micro-cap investing particularly well. The trade-off is that you take on discount/premium risk instead, which open-ended fund investors don't face.

An alternative angle: companies that lend to small businesses

small-cap economyIf you want exposure to the UK small and mid-sized business economy without buying an equity fund, another approach is to invest directly in the (larger, listed) companies that provide finance to smaller businesses — effectively backing the "picks and shovels" of the . UK-listed examples include non-bank lenders such as Funding Circle Holdings, Distribution Finance Capital Holdings, Mercia Asset Management, and Time Finance. This isn't a substitute for a diversified small-cap fund — it's a concentrated bet on individual lending businesses, each carrying its own credit and business risk — but it's worth knowing about as a genuinely different way to play the same underlying theme.

How to choose a UK small-cap fund or trust: a decision framework

Decide: trust or open-ended fund? If you're comfortable monitoring a discount/premium and want the structural liquidity protection described above, a trust may suit better. If you'd rather deal simply at NAV and avoid discount risk, an open-ended fund may be the more straightforward choice.
Check the investment style. Value-led funds (Aberforth, Rockwood Strategic) and quality/growth-led funds (Unicorn, JUGI) behave differently across market cycles — a portfolio blending both styles will typically be smoother than one concentrated in a single style.
Look at market-cap focus. Some funds and trusts (Rockwood Strategic, WS Gresham House UK Micro Cap) deliberately target the smallest, least-researched end of the market for higher potential returns and higher volatility; others sit further up the small-cap range.
Review the discount (for trusts) against its own history. A trust trading wider than its five-year average discount may represent value, but check why — sustained underperformance is a different story from temporary sentiment.
Check liquidity and size. Very small trusts and funds can themselves be harder to trade in size; larger vehicles like Aberforth Smaller Companies or the enlarged BlackRock Smaller Companies offer more liquidity.
Confirm ongoing charges. Specialist smaller-companies mandates typically cost more than mainstream UK equity funds — check the current ongoing charges figure (OCF) before comparing net returns.

Frequently Asked Questions

What is a small-cap fund?

A fund that invests in the shares of smaller listed companies — in the UK, generally those outside the FTSE 100 and FTSE 250, including many AIM-listed businesses.

What counts as "small-cap" in the UK?

There's no single official threshold, but small-cap typically refers to companies below roughly £500 million–£1 billion in market value, with "micro-cap" describing an even smaller tier, often under £250 million.

Are UK small-cap funds a good investment right now? UK small-caps have underperformed for several years and now trade at depressed valuations relative to history, with falling interest rates and rising takeover activity cited by several managers as supportive factors. This is not a guarantee of future performance, and small-caps remain a higher-volatility part of the market — this article is information, not personal advice.

What's the difference between a small-cap fund and a small-cap investment trust?

An open-ended small-cap fund deals daily at net asset value. A small-cap investment trust is a closed-ended company whose share price can trade above or below its NAV, but which isn't forced to sell holdings to meet redemptions — an advantage in a less liquid asset class like small and micro-caps.

What are the best-performing UK small-cap investment trusts?

Based on data reported during 2026, Rockwood Strategic has led the AIC UK Smaller Companies sector over three and five years, with JPMorgan UK Smaller Companies Growth & Income, BlackRock Smaller Companies (post its 2026 merger with Throgmorton), Rights & Issues, and Aberforth Smaller Companies also among the sector's stronger long-term performers.

What happened to BlackRock Throgmorton?

It merged into BlackRock Smaller Companies Trust in April 2026, creating an enlarged ~£780 million trust co-managed by both funds' former lead managers. Throgmorton no longer trades as an independent listed company.

Are small-cap funds riskier than large-cap funds?

Generally, yes. Smaller companies tend to be more volatile, less liquid, and more sensitive to the domestic economy and financing conditions than large, diversified blue-chip companies, which is why small-cap funds are usually held as part of a diversified portfolio rather than as a sole equity holding.

Can I get UK small-cap exposure without buying a fund?

Yes — some investors choose to buy shares directly in listed companies that finance UK small and mid-sized businesses (such as non-bank lenders), which offers indirect exposure to the small-business economy, though with concentrated single-stock risk rather than the diversification a fund provides.

Conclusion

UK small-caps sit in an unusual position: a sector that has disappointed for years but now carries several genuine, evidenced reasons for renewed interest — falling rates, depressed valuations and rising takeover activity among them. Whether an investment trust or an open-ended fund suits you better comes down largely to how you feel about discount risk versus forced-selling risk, which this guide's comparison table above is designed to help you weigh up.

AIC investment trusts Schiehallion FundIf smaller UK companies are just one part of a wider investment trust strategy you're building, our guide to explains how sectors, rankings and Dividend Heroes work across the whole trust universe, and if you're curious about the other end of the risk spectrum — unlisted, pre-IPO companies — see our explainer on the. This article is for information only and isn't a personal recommendation; always do your own research, and consider speaking to a regulated financial adviser before investing.

Best UK Small-Cap Funds and Trusts: How to Compare Your Options

UK smaller companies have had a rough few years. Persistent outflows from the sector, higher interest rates