Total expense ratio: how ETF costs affect long-term portfolio returns

The total expense ratio is the annual cost of owning an ETF, expressed as a percentage of assets under management. Because the TER is deducted from the fund's assets continuously rather than charged as an explicit fee, it is easy to underestimate its long-run impact. Over a 20-year holding period, a difference of 0.3 percentage points in annual costs compounds into a meaningful gap in terminal wealth.

What the total expense ratio is

The TER is the broadest cost measure for an ETF. It covers the management fee paid to the fund manager, administrative costs, custody fees, regulatory costs, and index licensing fees paid to the index provider. It does not capture all costs an investor bears—transaction costs when buying or selling the ETF on the exchange (the bid-ask spread) and brokerage commissions are not included in the TER—but it is the primary measure for comparing the ongoing cost of holding one ETF against another.

The TER is sometimes referred to as the ongoing charges figure (OCF) in European fund disclosure documents. The two terms are used interchangeably in most contexts, though the OCF calculation may exclude some costs—such as certain transaction costs within the fund—that can appear elsewhere in fund reporting.

How it works

The TER is not deducted in a single annual payment. Instead, the fund manager accrues the cost daily as a fraction of the fund's NAV. The effect is that the ETF's NAV grows slightly more slowly than the gross return of the index it tracks—by approximately the TER each year, before other sources of tracking difference are considered. An investor who holds an ETF with a TER of 0.20% per year will see their investment grow at the index return minus approximately 0.20%, assuming all other factors are equal.

The compounding effect of fees is significant over long periods. An investment of USD 100,000 compounding at 7% per year for 20 years grows to approximately USD 387,000. The same investment in a fund charging 0.50% per year (net return 6.5%) grows to approximately USD 352,000—a difference of USD 35,000, or roughly 9% of the final portfolio value, attributable entirely to the annual cost drag.

ETF costs have fallen substantially over the past two decades, driven by competition among index providers and ETF issuers. Large-cap equity ETFs from major providers are now available at TERs of 0.03–0.10% per year. More specialised ETFs—tracking emerging market small-caps, niche factor indexes, or commodity futures—typically carry TERs of 0.30–0.70% per year, reflecting higher replication costs and smaller assets under management.

What the evidence shows

Research on mutual fund and ETF performance has consistently found that costs are one of the most reliable predictors of relative returns. Lower-cost funds outperform higher-cost funds within the same category more often than not, precisely because both are tracking similar market returns and costs are deducted with certainty while outperformance is not guaranteed. Studies by Morningstar covering the period 2010–2020 found that the cheapest quintile of funds in most categories outperformed the most expensive quintile over 10-year periods, with the cost advantage explaining much of the return differential.

The TER is, however, an imperfect proxy for the actual cost of owning an ETF. The tracking difference—the gap between the ETF's actual annual return and the index return over the same period—is a more direct measure. Tracking difference can be smaller than the TER if the fund earns securities lending income that offsets part of its costs, or larger if transaction costs and other frictions compound the expense. Some large equity ETFs report tracking differences that are actually negative (the fund slightly outperforms its index) because securities lending revenue more than offsets the TER.

Limitations and trade-offs

The TER is a stated cost that may not reflect the total cost of ownership. Investors comparing ETFs on TER alone may overlook differences in tracking difference, bid-ask spread at the time of purchase, and securities lending practices. A fund with a higher TER but better securities lending income may be cheaper to hold than a fund with a lower TER but inferior execution.

For short holding periods, the bid-ask spread and brokerage commission matter more than the TER. For a holding period of one year or less, a bid-ask spread of 0.10% is more significant than the difference between a 0.07% and a 0.20% TER. For long-term, buy-and-hold positions, the TER becomes increasingly significant as it compounds over time.

Very low TERs can also be a source of confusion. A fund with a TER of 0.03% is not materially cheaper to hold than one at 0.07%—the difference is three basis points per year, which is negligible against equity market return variability. The important distinction is between low-cost index ETFs as a category and higher-cost active or niche ETFs, not between the cheapest options within the low-cost tier.

Total expense ratio in pfolio

When constructing portfolios in pfolio, the ETFs available span a range of asset classes and cost levels. The TER for each ETF is visible in the Assets section alongside other fund characteristics. Because pfolio applies monthly rebalancing rather than buy-and-hold, the transaction costs associated with trading also contribute to portfolio costs over time—the TER represents only the ongoing ownership cost, not the full cost of the portfolio strategy.

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