Index Funds vs Active Funds UK 2026: Costs, Performance and Which to Choose

Index funds vs active funds: The cost structure

The fundamental difference between index funds and active funds is cost. Index funds simply track a market index (e.g., FTSE 100, S&P 500, FTSE All-World), while active funds employ managers attempting to beat the index through stock selection or market timing.

Index fund costs (TER)

Index funds (also called trackers) aim to replicate the performance of an index with minimal deviation. Because they simply hold all (or a representative sample of) index holdings, costs are minimal.

FTSE All-World Index tracker TER (June 2026):

S&P 500 Index tracker TER:

The cheapest index funds charge 0.05-0.08% annually, making them extremely cost-effective for buy-and-hold investors.

Active fund costs (TER)

Active funds employ managers, analysts and traders to attempt to beat the market. This research and management costs significantly more.

UK Equity active fund TER (June 2026):

International equity active fund TER:

Active funds typically charge 0.75-1.5% TER. Some funds add performance fees (2-3% on outperformance), further increasing costs.

Fee comparison: 10-year cost impact

Let's compare the cumulative cost of fees over 10 years for GBP 50,000 invested.

Scenario: GBP 50,000 invested in index vs active fund

Assumption: 6% annual return (gross, before fees)

Index fund (TER 0.10%):

• Annual fee: GBP 50 (Year 1), growing as fund grows
• 10-year gross value (before fees): GBP 89,542
• 10-year net value (after fees): GBP 88,945
• Total fees paid: GBP 597

Active fund (TER 0.90%):

• Annual fee: GBP 450 (Year 1), growing as fund grows
• 10-year gross value (before fees): GBP 89,542
• 10-year net value (after fees): GBP 82,450
• Total fees paid: GBP 7,092

Fee difference: GBP 6,495 over 10 years (10-fold more fees in the active fund).

Scenario: GBP 50,000 invested over 30 years

Index fund (TER 0.10%):

• 30-year value at 6% return: GBP 435,820
• Total fees paid (compounded): ~GBP 20,000
• Net return: 5.90% annually

Active fund (TER 1.00%):

• 30-year value at 6% return: GBP 370,100
• Total fees paid (compounded): ~GBP 85,000
• Net return: 5.00% annually

Cost of higher fees: GBP 65,720 in lost growth (15% lower final value).

Over 30 years, a 0.90% fee difference compounds to GBP 65,000+ in lost returns on a modest GBP 50,000 initial investment.

SPIVA data: Do active funds outperform?

S&P Indices Versus Active (SPIVA) publishes periodic data on active fund performance vs their benchmark index. The 2025 data (most recent) covers 10-year performance periods.

Key SPIVA findings (2025, covering 2015-2025):

UK Equity funds:

• 87% underperformed FTSE All-Share index
• Only 13% outperformed (but after fees, actual outperformance is near zero)
• 5-year data: 84% underperformed

US Equity (S&P 500) funds:

• 92% underperformed S&P 500 index
• Only 8% outperformed
• 5-year data: 90% underperformed

Global Equity funds:

• 88% underperformed global index
• Only 12% outperformed
• Worse in equity-heavy periods

Bond funds:

• 81% underperformed bond index
• Better than equities, but still majority underperform

Key takeaway: 85-90% of active managers underperform their benchmark index. After fees, the percentage is even higher (most of the 10-15% that beat the index do so by less than their fee).

The luck vs skill problem

SPIVA data also shows that the managers who outperformed in one period are often different managers in the next period. This suggests that outperformance is often luck, not skill.

Example: Manager A outperforms in 2020-2025 (5-year period). In the next 5-year period (2025-2030), Manager A typically underperforms, while Manager B (who underperformed previously) now outperforms.

This pattern suggests that identifying future outperformers in advance is nearly impossible. By the time you identify a successful manager, their outperformance may already be priced into the fund's valuation, or they may move on to a different role.

When active funds might outperform

While the data overwhelmingly favours passive (index) funds for most asset classes, a few areas remain where active management may add value:

1. Emerging markets

Emerging market data is less complete, analyst coverage is thinner, and price inefficiencies may exist. Some active managers specialising in emerging markets have outperformed indices, though this is inconsistent.

SPIVA data: 65-70% of emerging market active funds underperform (vs 85-90% for developed markets).

2. Small-cap and mid-cap stocks

Small companies are followed by fewer analysts, and information asymmetry is higher. Some active small-cap managers have outperformed, though the effect is small.

Risk: Higher fees for small-cap funds (1.0-1.5% TER) can easily offset any outperformance.

3. Bond markets (especially credit/high-yield)

Bond pricing is complex, and credit analysis requires expertise. Some active bond managers have added value by identifying mispriced credit risk.

SPIVA data: 60-70% of bond funds underperform, better than equities but still majority underperform.

4. Absolute return or market-neutral strategies

Funds using hedging, short strategies, or complex derivatives sometimes outperform in down markets (though data is mixed).

Risk: High complexity, often high fees (1.5-2.5% TER + 20% performance fee), and significant downside in crashes.

Platform charges: Another layer of fees

Many investment platforms charge an annual fee on top of the fund's TER. This can add 0.25-0.50% to your total annual cost.

Example total annual charges:

Impact: Platform fees can more than double your total cost. When choosing a fund, ensure you compare total cost (TER + platform fee), not just fund TER.

Tax wrapper advantages

Both index and active funds can be held in ISAs or SIPPs, which provide tax-free growth (ISA) or tax-deferred growth (SIPP). The tax efficiency advantage is the same for both, so fund type (active vs index) is what differentiates.

Index funds in ISA/SIPP: Best overall cost structure

Active funds in ISA/SIPP: Still carry high TER, but tax-free growth means no additional tax cost

Using a tax wrapper is essential for both. Don't hold investments outside ISA/SIPP unless they're your only option.

Worked example: GBP 10,000 invested for 25 years

Scenario: A 40-year-old invests GBP 10,000 in either an index fund or active fund, hoping to retire at 65.

Index fund (FTSE All-World, TER 0.10%, via Vanguard ISA):

• 25-year value at 6% annual return: GBP 42,919
• Total fees paid: ~GBP 2,400
• Average annual fee (compounded): GBP 96/year

Active fund (Global Equity, TER 1.0%, via Interactive Investor ISA):

• 25-year value at 6% annual return (before fees): GBP 42,919
• After 1.0% TER: GBP 38,800
• After 0.25% platform fee: GBP 37,900
• Total annual cost: 1.25%
• Total fees paid: ~GBP 5,019
• Net value: GBP 37,900 (vs GBP 42,919 in index)

Cost of active fund: GBP 5,019 in fees, resulting in GBP 5,019 less wealth at retirement.

Recommended approach: Hybrid strategy

Most financial advisers recommend a core-satellite or hybrid approach:

1. Core (80%): Index funds tracking broad indices (FTSE All-World, S&P 500)

   • Lowest cost, passive, diversified
   • Forms the foundation of portfolio

2. Satellite (20%): Niche active funds in areas where active might add value

   • Emerging markets active fund
   • Small-cap active fund
   • High-yield bond active fund
   • Only add these if you believe the manager has skill

This approach keeps overall portfolio cost low (blended TER ~0.3-0.4%) while allowing for some active management in higher-conviction areas.

Building an index fund portfolio: Practical recommendations

Bare-minimum (simplest) portfolio

• 1 fund: FTSE All-World tracker (global diversification in one fund)
• TER: 0.10%
• Platform: Vanguard ISA
• Total cost: 0.10%

Diversified index portfolio

Blended TER: 0.085% (on invested portion)

This portfolio is globally diversified, low-cost, and easy to maintain.

Summary and recommendation

Index funds are appropriate for 85-90% of investors. Active funds rarely outperform after fees, SPIVA data shows persistent underperformance, and fee differences compound over time to create massive wealth gaps.

Choose index funds if you:

• Want a simple, low-cost portfolio
• Believe markets are reasonably efficient
• Don't have time to monitor manager performance
• Want to avoid paying GBP 5,000-10,000 in unnecessary fees

Consider active funds only if you:

• Specialise in a niche area and believe you can identify skilled managers
• Are willing to accept 85-90% probability of underperformance
• Have conviction in a specific strategy (emerging markets, small-cap)

For most investors, a portfolio of low-cost index funds, held in an ISA or SIPP, will outperform the majority of actively managed portfolios over a 20+ year horizon.

Use the

to model the impact of different fee levels on your retirement savings.