Ask ten UK investors to explain the difference between a unit trust and an investment trust, and at least half will describe something closer to an ETF. It's an understandable mix-up — both wrap up a basket of shares, both get sold through the same platforms, and the marketing on comparison sites rarely bothers to draw the line. But the structural difference between the two is not a technicality. It changes how your money behaves when markets get rough, what you actually pay in charges, and — critically — whether the price you see on screen has any relationship to what the fund is actually worth.
Two structures, one confusing choice
A unit trust and its close cousin, the OEIC (open-ended investment company), work the way most people assume all funds work. When you invest, the fund manager creates new units or shares specifically for you, using your cash to buy more of the underlying stocks. When you sell, those units are cancelled and the manager sells a matching slice of the portfolio to pay you out. The price you get is always tied directly to the net asset value (NAV) of the fund — the sum of everything it holds, divided by the number of units in issue. There's no buyer needed on the other side of your trade because the fund itself is the counterparty.
An investment trust is a different animal entirely, and this is the part that catches newcomers out. It's a listed company on the London Stock Exchange, with a fixed number of shares in issue, just like Tesco or Unilever. When you buy an investment trust, you're not creating new capital inside the fund — you're buying existing shares from another investor who wants to sell. The trust's managers never have to hand back cash on demand, which is precisely why investment trusts can hold illiquid assets — unlisted companies, infrastructure projects, ground rents — that an open-ended fund legally cannot touch in any meaningful size.
What happens when everyone wants their money back
Here's where the structural difference stops being academic. In June 2019, the Woodford Equity Income Fund suspended withdrawals because too many investors tried to sell at once and the manager couldn't liquidate the illiquid holdings fast enough to pay them. That's the open-ended structure's core vulnerability: a mismatch between daily-dealing promises and the actual liquidity of what's inside the fund. Investors who wanted out on a Monday morning were still locked in months later.
An investment trust simply cannot gate in that way. If you want to sell your shares in Scottish Mortgage or 3i Group on a Tuesday afternoon, you sell them on the stock exchange to another buyer, exactly as you'd sell any other share — the trust itself never has to raise cash to fund your exit. The trade-off is that the price you get depends on what a buyer is willing to pay right now, not on the underlying NAV. During periods of panic, that price can fall much further and much faster than the actual value of the portfolio underneath it.
The gearing question nobody explains properly
Investment trusts can borrow money to invest more than the capital shareholders put in — a practice called gearing. A trust running at 10% gearing effectively invests £110 for every £100 shareholders contribute, using debt to fund the difference. When markets rise, gearing amplifies returns; when they fall, it amplifies losses in exactly the same proportion. Unit trusts and OEICs are not permitted to gear in this way under FCA rules, which is one of the few genuinely unqualified structural advantages open-ended funds have over their listed cousins. Whether gearing suits you depends entirely on your time horizon and stomach for volatility. For a long-term holding inside a Stocks and Shares ISA where you won't need the money for fifteen years, modest gearing on a well-run global trust is a reasonable way to enhance long-run returns. For a short-term holding you might need to cash in within two or three years, avoid geared trusts altogether — the added volatility works against you exactly when you can least afford it.
Discounts and premiums — the bit that scares off beginners
Because investment trust shares trade on the open market, the price can sit above or below the NAV of the underlying portfolio. A trust trading at a 10% discount means you're buying £100 of assets for £90 — in theory, a bargain. Trading at a premium means paying more than the assets are actually worth, which happens with genuinely popular trusts during periods of high demand.
Discounts can persist for years, though, and a cheap-looking discount is not automatically a buy signal. Some trusts trade at a permanent structural discount because the sector is out of favour, the manager has an underwhelming track record, or the trust is simply too small and illiquid for institutional buyers to bother with. Baillie Gifford's smaller trusts have occasionally sat on double-digit discounts for extended stretches without narrowing, which is exactly the trap that catches investors who assume a wide discount must eventually correct.
Check the discount history on a site like the Association of Investment Companies (theaic.co.uk) before assuming a wide gap is a buying opportunity rather than a warning sign.
Costs: the ongoing charge isn't the whole story
On headline fees, investment trusts usually win. A typical actively managed global equity investment trust charges an ongoing charge figure (OCF) somewhere around 0.4%–0.9%, while a comparable actively managed unit trust or OEIC often sits closer to 0.75%–1.2%. Passive index-tracking OEICs and unit trusts can undercut both, with some FTSE-tracking funds charging under 0.1%.
But the OCF only tells part of the story for investment trusts. Because you're buying and selling shares on an exchange, you'll also pay a bid-offer spread and, depending on your broker, a dealing commission on each transaction — costs that don't apply in the same way to open-ended funds bought directly through most platforms. For someone drip-feeding £100 a month into a portfolio, those trading costs on an investment trust can quietly outweigh the lower OCF. For a lump-sum investor making a handful of trades a year, the maths tilts firmly the other way.
Which one actually suits you
If you're investing small, regular amounts — a standing order of £50 or £100 a month into a Stocks and Shares ISA — choose a low-cost index-tracking OEIC or unit trust over an investment trust. The dealing costs on frequent small trades will eat into an investment trust's fee advantage faster than most people expect, and open-ended funds are built specifically for that drip-feed pattern.
If you're investing a lump sum for the long term and want exposure to less liquid assets — renewable energy infrastructure, private equity, specialist property — an investment trust is usually the better vehicle, and this is where the sector earns its reputation. Trusts like Renewables Infrastructure Group or HICL Infrastructure hold assets that no open-ended fund could responsibly offer daily liquidity on, precisely because the underlying investments take months to sell, not days.
There's a middle case worth naming directly: someone who already holds a decent core of index trackers and wants to add active, differentiated exposure without paying platform trading fees on every top-up. For that investor, a monthly savings plan into an investment trust through a platform offering free regular investing (several UK brokers, including Hargreaves Lansdown and AJ Bell, run these schemes with reduced or waived dealing charges on scheduled purchases) removes the cost objection almost entirely.
Platform mechanics worth checking before you buy
Not every platform treats the two structures equally. Some SIPP and ISA providers charge a flat percentage platform fee on OEICs and unit trusts but a capped fee on shares and investment trusts — which matters enormously once your portfolio passes roughly £50,000, where a percentage fee on funds can end up costing more in cash terms than a capped fee on trusts. Check your platform's fee schedule against both fund types before assuming the underlying investment cost is the only number that matters. Dividend reinvestment is another practical difference. Most OEICs and unit trusts offer automatic, cost-free reinvestment of income. Investment trusts usually require you to opt into a dividend reinvestment plan (DRIP) separately, and some brokers charge a small fee — often a few pounds — per reinvestment. It's a minor cost individually, but across a 20-year holding period with quarterly dividends, those small charges add up into a figure worth checking before you commit to a trust as your core long-term holding.
The case that doesn't fit neatly either way
Emerging market and specialist Asia-focused trusts are where this whole comparison gets genuinely complicated, because both the liquidity risk and the discount risk are larger than in mainstream global trusts. A trust holding frontier-market equities can trade at a discount for structural reasons that have nothing to do with the manager's skill — currency controls, capital restrictions, or simply a shortage of UK buyers interested in that specific market. An equivalent open-ended fund sidesteps the discount risk but inherits the same underlying liquidity fragility that caused the Woodford suspension, just in a different asset class.
Neither structure removes the underlying risk of the assets themselves — it just changes where that risk shows up. That's the one thing worth holding onto once you've decided which wrapper to use: the choice between investment trust and unit trust changes how you experience volatility, not whether the volatility exists in the first place.