What is the difference between passive and active investing?
Passive investing involves buying funds that track a market index (such as the FTSE 100, S&P 500, or a global equity index) as closely as possible. The fund manager does not attempt to pick winning stocks or time the market — they simply replicate the index. Active investing involves fund managers using research, analysis, and judgment to select investments they believe will outperform the market.
This distinction matters enormously for UK investors because the approach you choose has a significant impact on your long-term returns, costs, and the amount of effort required to manage your portfolio. The debate between passive and active investing is one of the most important in personal finance.
The case for passive investing
The evidence overwhelmingly supports passive investing for most retail investors. According to the S&P SPIVA scorecard, which tracks fund manager performance, approximately 80–90% of actively managed UK equity funds underperform their benchmark index over a 10-year period after fees. Similar results are found across other markets and time periods.
The reasons for this consistent underperformance include:
- Higher fees: Active funds charge annual fees of 0.5–1.5%, while passive index funds charge 0.05–0.25%. Over decades, this fee difference compounds dramatically
- Trading costs: Active managers buy and sell frequently, incurring dealing costs and bid-ask spreads that reduce returns
- Cash drag: Active funds typically hold a portion of assets in cash to meet redemptions, which reduces exposure to market returns
- The zero-sum game: In aggregate, active managers are the market (minus costs). For every manager who outperforms, another must underperform by an equivalent amount
The case for active investing
Despite the statistical odds, there are scenarios where active management can add value:
- Less efficient markets: In emerging markets, smaller companies, and specialist sectors, markets may be less informationally efficient, giving skilled managers more opportunity to outperform
- Specific objectives: Active managers can tailor portfolios to specific goals, such as income generation, ethical investing, or capital preservation in volatile markets
- Downside protection: Some active strategies aim to participate in market rises while limiting losses during downturns, though few consistently achieve this
- Access to unlisted investments: Certain active funds invest in assets not available through index tracking, such as private equity or infrastructure
The challenge is identifying in advance which active managers will outperform. Past performance is a poor predictor of future results — a fund that has beaten its benchmark over the last five years is no more likely to do so over the next five. Persistence of outperformance among fund managers is remarkably rare.
💡 A common compromise is the core-satellite approach: build the core of your portfolio (60–80%) with low-cost passive index funds, then allocate a smaller portion (20–40%) to carefully selected active funds in areas where you believe active management can add value. This keeps overall costs low while allowing for potential outperformance.
Comparing costs: the compounding effect of fees
The long-term impact of fees is often underestimated. Consider a £100,000 investment growing at 7% per year before fees over 30 years. With a passive fund charging 0.15% per year, the final value would be approximately £720,000. With an active fund charging 1.00% per year, the final value would be approximately £574,000. That 0.85% fee difference costs you approximately £146,000 — over 20% of your total return erased by higher fees.
This illustration assumes the active fund matches the market's gross return, which as we have seen, most do not. When you factor in the likely underperformance of most active funds, the gap widens further.
Types of passive funds available in the UK
UK investors have access to a wide range of passive investment options:
- Index tracker funds (OEICs/unit trusts): Mutual funds that replicate an index. Bought and sold at the day's closing price. Minimum investments from £1 to £1,000
- Exchange-traded funds (ETFs): Trade on stock exchanges like shares, with prices updating throughout the day. Often marginally cheaper than equivalent tracker funds
- Multi-asset passive funds: Blend equities and bonds in a single fund at different risk levels (e.g., Vanguard LifeStrategy range). Ideal for investors wanting a simple, diversified portfolio
Key passive fund providers in the UK include Vanguard, iShares (BlackRock), Legal & General, HSBC, and Fidelity, all offering broad ranges of index-tracking products.
⚠️ Not all passive funds are created equal. Tracking error (the difference between the fund's return and the index return) varies between providers. Also check the fund's total cost, including the ongoing charges figure (OCF), platform fees, and any dealing charges. A cheap fund on an expensive platform can still be costly overall.
Building a passive portfolio
A globally diversified passive portfolio can be built with as few as one or two funds. A global equity index fund gives you exposure to thousands of companies across developed and emerging markets. Adding a global bond fund provides diversification and reduces volatility for more cautious investors. The split between equities and bonds should reflect your investment horizon and risk tolerance.
Get expert help with your investment strategy
Whether you lean towards passive investing, active management, or a combination of both, a qualified financial adviser can help you build a portfolio aligned with your goals, risk tolerance, and tax position. They can also help you choose the right platform, select appropriate funds, and structure your investments tax-efficiently.
Nesto connects you with FCA-regulated savings and investment advisers who can provide personalised guidance on building your investment portfolio. Get free, no-obligation advice today.