Open-Ended vs Closed-Ended Funds: Which Structure Suits Your Portfolio?

The Fundamental Difference

Investment funds can be structured in two fundamentally different ways, and the difference matters more than many investors realise.

An open-ended fund stands ready to accept new money from investors and to return money to investors who want to exit. When you invest, the fund creates new units or shares for you at the current net asset value (NAV). When you want your money back, the fund cancels your units and returns cash, selling underlying assets if necessary. The fund's total assets grow and shrink with investor demand.

A closed-ended fund issues a fixed number of shares through an initial public offering and then lists those shares on a stock exchange. If you want to invest, you buy existing shares from another investor. If you want to exit, you sell your shares to another investor. The fund manager never needs to create or cancel shares, and never needs to buy or sell underlying assets simply because investors want in or out.

This structural difference — simple in description, profound in consequence — determines what each type of fund can sensibly invest in, how it prices, and what risks it carries.

Open-Ended Funds: OEICs, Unit Trusts, and Mutual Funds

The UK Variants

In the UK, open-ended funds take two main forms:

Unit trusts are the older structure, dating back to the 1930s. Investors hold "units" in a trust. The trustee holds legal title to the assets; the unit holders have beneficial ownership. Unit trusts have a bid/offer spread — the price at which you buy (offer) is higher than the price at which you sell (bid). This spread, typically 5–6% historically but narrowed or eliminated by many modern unit trusts, represents a cost of entry and exit.

OEICs (Open-Ended Investment Companies) are the corporate form introduced in the 1990s and now the dominant structure for new UK funds. Investors hold shares rather than units. OEICs typically operate on a single price (the NAV), though a dilution levy may be applied to large transactions to protect existing investors from the cost of large inflows or outflows. Most fund groups have converted their unit trusts to OEICs over the past two decades.

Economically, unit trusts and OEICs are effectively identical for the retail investor. Both offer daily pricing and daily liquidity, both are regulated under UCITS (for those marketed to retail investors), and both hold diversified portfolios of eligible assets.

The Liquidity Constraint — and Why It Matters

The defining feature of an open-ended fund is the promise of liquidity — investors can exit at NAV on any dealing day. This promise has consequences:

The fund must hold sufficient liquid assets to meet redemption requests. A fund that invested entirely in illiquid assets would face a crisis if many investors tried to exit simultaneously: selling illiquid assets quickly requires accepting large discounts, depressing NAV and triggering more redemptions in a self-reinforcing spiral.

This is not hypothetical. Several high-profile property funds suspended dealing in 2016 (following the Brexit referendum) and again in 2020 when they could not sell properties quickly enough to fund redemptions. The Woodford Equity Income Fund suspended dealing in 2019 after overconcentrating in illiquid unlisted companies — a classic open-ended fund investing in assets unsuited to its structure. Investors in suspended funds cannot access their money until the manager can sell enough assets to fund withdrawals.

The lesson: open-ended funds are appropriate for liquid assets (listed equities, government bonds, investment-grade corporate bonds). For illiquid assets, the closed-ended structure is structurally superior.

Closed-Ended Funds: Investment Trusts

The UK Investment Trust

The investment trust is the UK's closed-ended fund structure, with a history stretching back to 1868 (the Foreign & Colonial Investment Trust, still operating today as F&C Investment Trust). Investment trusts are listed companies whose business is investing in other assets.

Investors buy and sell investment trust shares on the London Stock Exchange exactly as they would shares in any other listed company. The share price is determined by supply and demand, not by the NAV of the underlying portfolio. This creates the premium and discount dynamic that is the defining feature — and specific risk — of the investment trust.

Premiums and Discounts

When an investment trust's shares trade at a price below the NAV of its underlying portfolio, the trust is said to trade at a discount. When shares trade above NAV, the trust trades at a premium.

Discounts and premiums are driven by sentiment, supply and demand, manager reputation, and market conditions. A well-regarded trust with a strong track record might consistently trade at a small discount of 2–3%. A trust in an out-of-favour sector might trade at a discount of 20–30%. In distressed markets, discounts can widen dramatically.

For buyers, a discount creates an interesting opportunity: you buy £1 of assets for 85p. If the discount narrows (either because the underlying assets perform well, or because sentiment improves), you benefit from two sources of return — the asset performance and the re-rating. For sellers, a discount is painful: you sell assets worth £1 for 85p.

Discounts can be permanent, or they can widen and narrow unpredictably. Investors should never assume that a discount will narrow on their timetable.

Buybacks and discount control. Investment trust boards can buy back shares in the market to narrow a discount, deploying cash from the trust's assets to purchase shares at below-NAV prices. This is theoretically value-accretive for remaining shareholders. Some trusts maintain tender offers or redemption facilities as additional discount-control mechanisms. However, these mechanisms are discretionary and not guaranteed.

Why Investment Trusts Suit Illiquid Assets

The closed-ended structure is ideal for illiquid asset classes:

Infrastructure. The major UK-listed infrastructure investment trusts (HICL Infrastructure, 3i Infrastructure, International Public Partnerships) invest in long-duration assets including roads, hospitals, schools, and regulated utilities. These assets cannot be sold quickly. Because the trust never faces redemptions, it can hold them indefinitely.

Private equity. Listed private equity trusts (3i Group, HarbourVest, Oakley Capital Investments) give retail investors access to private companies. The underlying stakes may take years to exit. The closed-ended structure means the manager can be patient.

Property. While there are listed REITs and property trusts that own physical real estate, the investment trust structure allows the manager to own the properties without the forced-sale risk that afflicts open-ended property funds.

Specialist lending and private credit. Various listed trusts provide returns from loans, mortgages, and other forms of credit that would be difficult to package in an open-ended structure.

Gearing

Investment trusts can borrow money to invest — a practice called gearing. Open-ended UCITS funds have strict limits on borrowing. Investment trusts can gear more aggressively.

Gearing amplifies both gains and losses. A trust with 20% gearing that invests in a market that rises 10% makes approximately 12% (10% return on the whole portfolio including the borrowed portion, less interest costs). If the market falls 10%, the trust loses approximately 12%. Gearing is a double-edged sword and investors should check each trust's current gearing level before investing.

ETFs: A Hybrid Structure

Exchange-Traded Funds combine features of both open-ended and closed-ended vehicles.

An ETF is technically open-ended: a mechanism operated by large institutional firms called "authorised participants" (APs) keeps the ETF price close to its NAV. If the ETF trades at a premium to NAV, APs buy the underlying assets, deliver them to the ETF manager, and receive new ETF shares to sell in the market — narrowing the premium. If the ETF trades at a discount, APs buy ETF shares and redeem them for the underlying assets — narrowing the discount.

This creation/redemption mechanism is invisible to retail investors but is essential to the functioning of ETFs. It means ETFs almost always trade very close to NAV, unlike investment trusts.

At the same time, ETFs trade on exchanges intraday like shares — unlike traditional open-ended funds, which price only once per day after market close. This gives ETFs a trading flexibility that OEICs and unit trusts do not have.

For most retail investors with a long-term perspective, the intraday trading flexibility of ETFs is irrelevant. What matters more is: the cost is typically very low; the structure is well-regulated (for UCITS ETFs); and for mainstream asset classes (developed market equities, government bonds), the ETF market is extraordinarily liquid.

Choosing Between the Structures

The choice between open-ended and closed-ended structures should be driven by the underlying asset class and your own investment approach:

Use open-ended funds (OEICs, unit trusts, ETFs) when:

• Investing in liquid asset classes: developed market equities, investment-grade bonds, money market instruments
• You want daily liquidity at NAV without exchange trading costs or bid/ask spreads
• You are investing regularly (pound-cost averaging) into a fund and want a simple, frictionless process

Use closed-ended funds (investment trusts) when:

• Accessing illiquid asset classes: private equity, infrastructure, direct property, specialist lending
• The discount/premium dynamic represents an opportunity rather than a risk (e.g., buying at a historically wide discount with strong underlying fundamentals)
• Gearing is appropriate to your investment case and you understand the amplification of both gains and losses
• You want exposure to sectors where the quality of management is particularly important (private equity selection, specialist infrastructure)

The Costs of Each Structure

All fund structures carry costs, but the nature of costs differs.

Open-ended funds (OEICs, unit trusts): ongoing charges figure (OCF) deducted daily from the fund's assets; no trading costs for the investor (though platform charges may apply); possible dilution levies on large transactions.

Investment trusts: ongoing charges (typically lower than active OEICs of comparable mandate, as trusts tend to be efficient structures); stockbroking commissions when buying and selling shares; stamp duty (0.5%) on purchase in the UK; the bid/ask spread on the stock exchange.

ETFs: very low OCF for passive ETFs; stockbroking commissions; bid/ask spread on the exchange (typically very narrow for major ETFs but can be wider for niche products); no stamp duty for UK-listed ETFs registered as exempt.

For long-term buy-and-hold investors in liquid asset classes, a low-cost UCITS ETF or OEIC index fund typically minimises total costs. For accessing alternative assets, the investment trust structure offers access that simply is not available in open-ended form.

Risk Considerations

Both structures carry investment risk — capital can fall as well as rise. The structural risks differ:

Open-ended funds: the primary structural risk is suspension of dealing when the underlying assets are insufficiently liquid. This risk is low for equity and bond funds but real for property, peer-to-peer lending, and other illiquid strategies.

Investment trusts: the primary structural risk is discount widening. A trust bought at NAV may trade at a 15–20% discount if sentiment deteriorates, even if the underlying assets are performing well. Gearing in investment trusts amplifies losses in falling markets. These risks are manageable but require understanding before investing.

Investment products can fall as well as rise in value. Past performance is not a guide to future results. Tax treatment and the regulatory framework may change. Seek professional financial advice before making investment decisions.

How Global Investments Can Help

Selecting between open-ended and closed-ended fund structures requires matching the structure to the asset class, your liquidity requirements, and your tax position. Our advisers can assess your portfolio, recommend the appropriate mix of UCITS funds, ETFs, and investment trusts for your investment objectives, and help you access the specialist closed-ended structures that provide exposure to private equity, infrastructure, and other illiquid premium-return assets. Contact us to discuss your portfolio.