TER and Tracking Difference: the real cost of your ETF
The TER displayed on the KID is not the real cost of your ETF. The Tracking Difference — the gap between the ETF's return and its index — is the only metric that measures what you truly pay. For some ETFs, the listed TER is 0.20% but the TD is negative: the ETF outperforms its index.
What is the TER?
The TER (Total Expense Ratio) is the annual percentage that an ETF issuer deducts from the fund's assets to cover its operating costs: administrative expenses, depositary fees, legal costs, and the issuer's margin. It is expressed as a percentage per year and deducted daily from the fund's net asset value, you never pay it directly; it is already embedded in the ETF's price.
The TER is the easiest cost figure to find: it appears on the front page of every ETF's KID (Key Information Document), mandatory in Europe since MiFID II. But it is also the most incomplete figure for assessing the true cost of an ETF.
Where to find an ETF's TER
The ETF's KID (under "Costs"), the product page on JustETF or the issuer's website (iShares, Amundi, Invesco, Vanguard). The TER is fixed and known in advance, unlike the tracking difference, which can only be observed after the fact.
Stated TER vs Tracking Difference: the real cost
The TER is not the cost you actually bear. What matters is the Tracking Difference (TD): the gap between the ETF's annual performance and that of its benchmark index. The TD incorporates the TER, but also other factors that can work in your favour or against you.
- Factors that improve the TD: securities lending income, withholding tax optimisation on dividends, synthetic replication efficiency (swap), corporate action proceeds.
- Factors that worsen the TD: transaction costs from rebalancing (stocks entering and leaving the index), cash drag (uninvested cash), entry costs in certain markets, currency conversion costs.
| ETF | Stated TER | Actual TD | Difference |
|---|---|---|---|
| CSPX | 0.07% | -0.02% | -0.09% |
| IWDA | 0.20% | 0.01% | -0.19% |
| WPEA | 0.19% | 0.10% | -0.09% |
| CW8 | 0.38% | 0.28% | -0.10% |
| SP5C | 0.09% | 0.05% | -0.04% |
Indicative average TDs over 3 years (2022-2025). The difference (TER - TD) represents income recovered via securities lending and optimisations. A negative TD means the ETF outperforms its index net of fees.
The key rule
Always compare the TD, not the TER alone. An ETF with a TER of 0.38% and TD of 0.28% (CW8) costs less than it appears. An ETF with a TER of 0.10% and TD of 0.25% would actually cost more than CW8. Find the TD on JustETF in the "Performance" tab by comparing the ETF to its benchmark over 1, 3, and 5 years.
Simulation: the impact of a 0.10% difference over 20 years
A TER gap of 0.10% may seem negligible. Over 20 years, with the power of compound interest, it represents a significant amount. Here is the simulation for €10,000 invested at 7% gross annual return, at different TER levels (assuming TER = TD for simplicity):
| Scenario | TER | Final capital | Lost to fees |
|---|---|---|---|
| No fees (pure index) | 0.00% | €38,697 | n/a |
| CSPX (iShares S&P 500) | 0.07% | €38,164 | -€533 |
| IWDA (iShares MSCI World) | 0.12% | €37,760 | -€937 |
| WPEA (Invesco MSCI World) | 0.19% | €37,337 | -€1,360 |
| CW8 (Amundi MSCI World) | 0.38% | €35,996 | -€2,701 |
| Average active fund | 0.50% | €35,027 | -€3,670 |
Simulation: €10,000 invested as a lump sum, 7% gross annual return, 20-year horizon. Fees are deducted annually on the outstanding balance (compound effect). Pre-tax.
Reading the figures
- Between CSPX (0.07%) and CW8 (0.38%), the gap reaches €2,168 over 20 years on €10,000 invested, 21% of the initial capital.
- Between CW8 (0.38%) and an average active fund (0.50%), the difference is €969, and active funds also tend to underperform their benchmark on top of their fees.
- A monthly contribution of €200 (rather than a lump sum) would amplify these gaps proportionally.
The cheapest ETFs in 2026
Here are the most widely used ETFs among French retail investors, sorted by ascending TER. The "PEA" column indicates eligibility for the French Plan d'Epargne en Actions tax wrapper.
| ETF | Index | TER | Avg TD | PEA |
|---|---|---|---|---|
| CSPX | S&P 500 | 0.07% | ~-0.02% | No |
| SP5C | S&P 500 | 0.09% | ~+0.05% | Yes |
| IWDA | MSCI World | 0.12% | ~-0.01% | No |
| WPEA | MSCI World | 0.19% | ~+0.10% | Yes |
| CW8 | MSCI World | 0.38% | ~+0.05% | Yes |
TER as of 01/05/2026. Indicative average TDs over 3 years. Source: issuer KIDs, JustETF. Verify eligibility with your broker before investing.
Key observation
CW8 (0.38%) has a TER almost 4x higher than CSPX (0.07%), but it is the only MSCI World ETF widely available on the French PEA with high liquidity. For a PEA investor, the tax advantage (17.2% vs 30%) more than compensates for this fee gap over the long term.
New ESMA 2026 cost transparency rules
Since January 2026, the European Securities and Markets Authority (ESMA) has strengthened transparency requirements on ETF costs as part of the MiFID II review. Three major changes affect retail investors:
- Mandatory 3-year TD publication : all UCITS ETF issuers must now display the annual tracking difference over 1, 3, and 5 years (where available) in the KID, not just the TER. This measure had been requested by investor associations since 2022.
- Securities lending revenue transparency : issuers must disclose the share of securities lending income returned to the fund (and therefore to investors) versus retained by the issuer. This information was previously buried in annual reports.
- Transaction costs included in reporting : costs related to index rebalancing must be estimated and disclosed separately. They typically range from 0.01% (S&P 500, very few changes) to 0.10%+ (small cap or emerging market indices, higher turnover).
What this changes in practice
Before 2026, comparing two MSCI World ETFs required consulting each issuer's annual report and manually calculating the TD. Since 2026, this information is standardised and directly accessible in the KID. Cost comparison is therefore easier, and issuers are incentivised to improve their efficiency to remain competitive.
How to factor the TER into your ETF selection
The TER is the starting point, not the conclusion. Here is a 4-step method for assessing the true cost of an ETF:
1. Note the TER
This is your first filter. Immediately rule out ETFs with a TER above 0.50% on standard indices (MSCI World, S&P 500, developed markets). For niche indices (small caps, specific emerging markets, thematic), a TER up to 0.60% may be justified by replication complexity.
2. Look up the Tracking Difference
On JustETF, in the Performance tab, compare the ETF's annualised return to its index over at least 3 years. The gap is the TD. A TD of 0.05% on an ETF with a TER of 0.20% means securities lending is returning 0.15% / year to you.
3. Account for the tax wrapper
A PEA-eligible ETF with a TER of 0.38% (CW8) beats a standard account ETF with a TER of 0.12% if you are in the 30% tax bracket. Over 20 years, the 12.8 percentage point tax gap far exceeds the 0.26% TER gap.
4. Check liquidity (spread)
A very cheap but illiquid ETF can cost you 0.20%+ on each buy and sell via the bid/ask spread. For ETFs with AUM above €500m, the spread is generally below 0.05%. This is a one-off cost, but worth factoring in if you invest regularly.
Frequently asked questions
Is the TER deducted automatically or do I pay it separately?▾
The TER is deducted automatically and daily from the fund's net asset value. You never receive a bill for this amount. In practice: if the MSCI World gains 7% in a year and the TER is 0.38%, your ETF shows a return of ~6.62% (before TD). You don't "pay" 0.38% of your capital each year, it is mechanically subtracted from the fund's valuation.
Why does CW8 have a TER of 0.38% while IWDA is at 0.20% for the same index?▾
Several factors explain the gap: CW8 uses synthetic replication (more complex to manage), is domiciled in France (higher regulatory costs), and benefits from historical brand recognition on the PEA. IWDA is domiciled in Ireland (favourable tax treatment of US dividends via the Ireland-USA tax treaty), uses large-scale physical replication (economies of scale across 1,434 securities), and its securities lending programme generates substantial income that partially offsets fees.
Can a negative tracking difference be sustained over the long term?▾
Yes, and CSPX (iShares S&P 500) has achieved this for several years: its TD is slightly negative (~-0.02%), meaning the ETF slightly outperforms its index net of fees. This is possible thanks to iShares' (BlackRock) securities lending programme, which generates income exceeding the 0.07% TER. This situation is harder to maintain on less liquid markets.
Should I choose CW8 or WPEA for a French PEA in 2026?▾
In 2026, WPEA (TER 0.19%, TD ~0.10%) is more efficient than CW8 (TER 0.38%, TD ~0.28%) on cost alone. The TD gap of 0.18% represents approximately €1,500 more over 20 years on €10,000 invested at 7%. CW8 remains relevant if your broker does not offer WPEA, or if you value CW8's superior liquidity (AUM ~€8.5bn vs ~€2.2bn for WPEA). Since WPEA's TER reduction in March 2026 (from 0.60% to 0.19%), WPEA's advantage has become clearly dominant.
Summary
The TER is a useful but incomplete indicator. The true cost of an ETF is measured by the Tracking Difference, which incorporates the TER, securities lending income, dividend tax optimisation, and transaction costs. For MSCI World exposure, WPEA (TD ~0.10%) is currently the cheapest PEA-eligible option, followed by CW8 (TD ~0.28%).
Over 20 years, a 0.10% fee gap represents approximately €1,000 on €10,000 invested at 7%, and a 0.50% gap (between a good ETF and an average active fund) represents more than €3,600. Choosing a low-TER ETF with a good TD is one of the most impactful decisions a retail investor can make.
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