What is the main difference between an ETF and a mutual fund?

Both are pooled investment vehicles that hold a basket of securities. The key differences: ETFs trade on stock exchanges throughout the day like individual shares; mutual funds (unit trusts and OEICs in the UK) are priced once per day and bought/sold directly with the fund manager. ETFs typically have lower fees, especially for passive index tracking. Mutual funds may have no dealing charges on some platforms, making them better for regular small contributions in some cases.

Are ETFs cheaper than mutual funds?

For passive index tracking, ETFs tend to be cheaper — many global index ETFs charge 0.05–0.22% per year. Comparable passive mutual funds charge 0.10–0.30%. The difference is small. However, active mutual funds charge significantly more — typically 0.5–1.5% per year — versus actively managed ETFs (rarer, but similarly expensive). For passive investing, both ETFs and passive index mutual funds are excellent low-cost options.

Should I choose an ETF or index fund for my ISA?

For most UK investors, both are equally good inside a Stocks and Shares ISA. On platforms like Vanguard Investor, the FTSE Global All Cap Index Fund (mutual fund, 0.23%) and FTSE All-World ETF (0.22%) are effectively identical in cost and exposure. Choose based on your platform's pricing: some charge a dealing fee per ETF trade but no charge on funds, making funds cheaper for small monthly contributions. On InvestEngine (0% fee on ETFs), ETFs are the clear winner.

ETFs vs Mutual Funds 2025 — Complete Comparison Guide

What Are They?

Both ETFs (exchange-traded funds) and mutual funds pool money from many investors to buy a basket of securities — shares, bonds, or other assets. The core difference is structural:

A mutual fund (called a unit trust or OEIC in the UK) is bought and sold directly through the fund manager or a platform. It's priced once per day after the market closes, at its Net Asset Value (NAV). You submit an order, and it's executed at the next day's price — you never know the exact price you'll pay when you submit the order.

An ETF trades on a stock exchange throughout the day, just like a share. You see the price before you buy, and your order is executed immediately at the current market price. ETFs can be bought and sold at any point during market hours.

The ETF vs mutual fund debate matters less than the active vs passive distinction. A passive ETF and a passive mutual fund tracking the same index are nearly identical in long-term outcome. The real battle is passive (low-cost, market-tracking) vs active (expensive, attempts to beat the market). For most investors, passive wins — regardless of whether it's packaged as an ETF or a fund.

Full Side-by-Side Comparison

Feature	ETF	Mutual Fund (Passive)
How you buy	Stock exchange, via broker	Direct from fund or via platform
Pricing	Real-time, throughout the day	Once daily, at close of market
Typical OCF (passive)	0.05–0.22%	0.10–0.30%
Dealing charges	Often £0–£10 per trade	Usually none on most platforms
Minimum investment	1 share (or fractional)	Often £1–£100/month
Regular investing cost	May incur per-trade fees	Usually free monthly contributions
Dividend handling	Accumulating or distributing	Accumulating or income units
Tax efficiency (outside ISA)	Generally more efficient (less turnover)	Similar for passive funds
Transparency	Holdings visible daily	Monthly/quarterly disclosure
Range on platforms	Very wide	Platform dependent
Suitable for small monthly amounts?	Depends on platform fees	Yes — usually no dealing charge

The Cost Battle: Real Numbers

For passive investing, the cost difference between ETFs and index mutual funds is minimal. The more important cost comparison is passive vs active:

Vanguard FTSE All-World ETF (VWRP): 0.22% OCF + dealing charge (varies by platform)
Vanguard FTSE Global All Cap Fund: 0.23% OCF, no dealing charge on Vanguard platform
Average UK active fund: 0.75–1.5% OCF + performance fees on some

On a £50,000 portfolio, the difference between a 0.22% passive fund and a 1.2% active fund is £490 per year — every year. Over 30 years, compounded, that fee drag costs approximately £90,000–100,000 in lost returns.

ℹ️ Platform fee matters too

When comparing ETFs vs funds, always include the platform fee in your calculation. On InvestEngine (0% on ETFs), an ETF is clearly cheapest. On a platform charging 0.25% on both ETFs and funds but with a £10 dealing charge per ETF trade, a fund may be cheaper for small monthly contributions (e.g. £100/month — a £10 dealing charge is 10% of your investment).

ETF or Mutual Fund: Which Should You Choose?

Choose ETF when...

ETF is the better choice

Your platform charges 0% or very low dealing fees (InvestEngine, Trading 212)

You're investing larger lump sums (£500+) where per-trade fee is negligible

You want intraday pricing flexibility

You want the widest possible fund choice

You want maximum transparency on holdings

Choose Mutual Fund when...

Fund is the better choice

Your platform charges a dealing fee per ETF trade but none for funds

You're investing small monthly amounts (£25–£200) via direct debit

You want to invest in a specific fund only available as a mutual fund

You prefer not to deal with intraday pricing complexity

✅ Bottom line

For most UK investors using a Stocks and Shares ISA: both passive ETFs and passive index mutual funds are excellent choices that will produce nearly identical long-term results. The decision comes down to your platform's specific fee structure. On Vanguard Investor, the fund is marginally better for regular contributions. On InvestEngine, ETFs are clearly better. Don't agonise — pick one and start investing. The difference between ETF and passive fund is tiny. The difference between starting now and waiting is not.

Active Mutual Funds: The Bigger Issue

The most important choice isn't ETF vs passive mutual fund — it's passive vs active. Active mutual funds employ professional managers to pick stocks and attempt to beat the market. They charge significantly more. And the data shows that over 10-year periods, roughly 85–90% of active funds underperform their equivalent passive index benchmark after fees.

If you're currently in an active fund (check if your fund's OCF is above 0.5%), it's worth reviewing whether switching to a passive index ETF or fund would serve you better. The maths usually favour the switch clearly.

Frequently Asked Questions

No — the risk profile of an ETF or mutual fund depends on what it holds, not its legal structure. A global equity ETF and a global equity mutual fund tracking the same index carry identical market risk. The ETF structure itself does not add risk. In fact, physical UCITS ETFs in the UK/EU have strong investor protections — assets are segregated from the fund manager's balance sheet.

Yes — within an ISA, you can sell a mutual fund and use the proceeds to buy an ETF without any tax implications. The transaction stays inside the ISA wrapper. Note that selling may take 1–3 business days for the mutual fund settlement, and ETF purchase settlement is typically T+2 (2 business days). Check if there are any early exit charges on the mutual fund first.

UCITS stands for Undertakings for Collective Investment in Transferable Securities — a regulatory framework that applies across the EU and UK. UCITS ETFs are regulated investment products with specific investor protections: diversification rules (no single holding can exceed 20% of the fund), clear disclosure requirements, and asset segregation from the fund manager. UK and EU investors should look for the UCITS label on any ETF they buy.

Important: Educational only. Not financial advice. Fund costs shown are indicative — always verify current charges with providers. Investing involves risk.