0.12% or 0.45% a year — at first glance, the gap looks trivial. Over a 20- or 30-year holding period, it isn't. Understanding how ETF costs are structured leads to a noticeably more informed decision.
What the TER actually is
TER stands for Total Expense Ratio. It's the percentage of assets under management charged every year to run the fund. The biggest line item is the provider's management fee — for a passive ETF, that mostly covers the technical work of tracking the index, not active investment decisions.
You never see the TER as a separate bill. It's deducted daily, pro rata, straight out of the fund's assets, which steadily drags on the ETF's performance. As an investor, you won't notice this day to day — the effect only shows up when you compare the ETF's return to the raw index it tracks.
Why ETFs are usually cheaper than active funds
Because an ETF only tracks an index instead of making active calls, it skips most of what drives up costs at a traditional fund: research teams, portfolio managers, frequent rebalancing. That shows up directly in the TER.
On broad index ETFs — the MSCI World or the S&P 500, for instance — TER today typically runs between 0.1% and 0.5% a year, and can dip even lower at particularly low-cost providers. Actively managed equity funds, by contrast, often charge 1% to 2% a year — a structural gap that exists regardless of whether the active fund happens to beat the market in any given year.
What the TER doesn't include
TER matters, but it's not the only cost component that comes with investing in ETFs:
Transaction costs. Buying and selling on an exchange means your broker charges an order fee. That depends on your broker, not the ETF itself.
Spread. This is the gap between the price you can buy at (ask) and the price you could sell at (bid). On highly liquid, broad ETFs, the spread is usually tight; on niche products with thin trading volume, it can be noticeably wider.
Tracking difference. This is the actual gap between an ETF's return and the return of its underlying index over a period. It's not the same as the TER, because other factors — securities lending, tax effects — play in too, but after the fact, it gives you the most honest read on how cost-efficient an ETF actually was.
Why small percentages matter enormously over time
Imagine two ETFs tracking the exact same index — one at 0.1% TER, the other at 0.4%. On a one-time $10,000 investment at an assumed 7% gross annual return over 30 years, that 0.3 percentage-point cost gap alone, purely through compounding, would translate into a meaningfully large difference in ending value — with identical market performance, driven entirely by cost structure. This is a simplified illustrative model, not a forecast for any specific product, but it makes the point: cost is one of the few factors in investing you can actually control.
What to check when comparing costs
Only compare TER between ETFs tracking the same or a very similar index — otherwise you're comparing different products with different risk-return profiles. Also glance at fund size (larger funds are less often at risk of closure) and historical tracking difference, where it's available.
Cost is an important building block — but only one. Just as important is how large a position is relative to your whole portfolio. With Axiomly's position size calculator, you can immediately see how much fits your personal risk budget — whichever ETF you end up choosing.