How Investment Fees Work: Expense Ratios, MERs, Trailers and the Cost of 1%

Investment fees are the costs you pay to own and trade investments: fund expenses, sales commissions, advisory fees, and trading costs. Most of them are charged as a small percentage of your balance every year, which makes them easy to overlook, but because they come out of a growing balance every year, they compound against you.

In short: a fee of 1% a year does not cost you 1% of your money. In our worked example below, it costs about a quarter of what you would otherwise have after 30 years. Many fees are taken inside the fund, so you never see a bill. Knowing which fees you pay, and what each one buys, is one of the few investing decisions fully within your control.

The main kinds of fees

Fund expenses: expense ratio (US) and MER (Canada)

Every mutual fund and ETF has ongoing costs: paying the managers, running the fund, legal and audit fees, and so on.

In the US, these are summarized as the expense ratio, shown in the fund’s prospectus fee table. See expense ratio.
In Canada, the equivalent is the management expense ratio (MER): the management fee plus operating expenses and sales taxes, as a percentage of average assets. It appears in the fund’s Fund Facts or ETF Facts document.

These costs are deducted from the fund’s assets daily, so the fund’s reported return is already net of them. You never write a cheque. A fund that holds $10,000 of your money with a 1% expense ratio costs you about $100 a year, whether or not you notice.

Trading costs inside the fund (commissions and spreads when the manager buys and sells) are usually not in the expense ratio or MER. Canadian funds report them separately as the trading expense ratio (TER). US funds disclose portfolio turnover, which hints at trading costs.

For scale: the Investment Company Institute’s Trends in the Expenses and Fees of Funds, 2024 reported US asset-weighted average expense ratios in 2024 of 0.64% for actively managed equity mutual funds, 0.05% for index equity mutual funds, and 0.14% for index equity ETFs.

Sales charges (loads)

Some mutual funds charge a commission to buy or sell:

A front-end load is taken from your purchase. With a 5% front-end load, $10,000 buys only $9,500 of fund units.
A back-end load, or in Canada a deferred sales charge (DSC), is charged when you sell, usually on a declining schedule over several years.

In the US, FINRA rules cap mutual fund sales charges, and many funds now offer no-load share classes. In Canada, the Canadian Securities Administrators (CSA) banned new sales of DSC funds as of June 1, 2022. DSC schedules on purchases made before that date were allowed to run their course.

12b-1 fees (US) and trailing commissions (Canada)

These are ongoing payments for selling and servicing the fund, built into the fund’s annual costs.

In the US, 12b-1 fees are paid from fund assets for distribution and shareholder services and are included in the expense ratio. FINRA caps them at 1% a year in total (0.75% for distribution plus 0.25% for service fees).
In Canada, trailing commissions (trailers) are paid by the fund company to the dealer that sold you the fund, out of the management fee, for as long as you hold it. The CSA’s Consultation Paper 81-408 (2017) described about 1% a year as typical for actively managed equity funds and 0.10% to 0.25% for passive funds.

Two important Canadian rule changes took effect on June 1, 2022: the DSC ban above, and a ban on paying trailing commissions to order-execution-only dealers, such as discount brokerages, that do not assess whether an investment is suitable for you. If you buy funds in a self-directed account, you should no longer be paying a trailer for advice you do not receive.

Many Canadian funds are offered in series. Advisor-sold series (often called A) have a trailer built in; fee-based series (often F) leave it out because you pay an advisor directly. The portfolio can be identical, with MERs that differ by about the size of the trailer.

Advisory fees

If you work with an advisor or a managed-account service, you may pay:

A percentage of assets each year (for example, 1% of a $500,000 account is $5,000 a year), charged on top of the funds’ own fees.
A wrap fee that bundles advice, trading, and administration into one percentage.
A flat or hourly fee, common with advice-only planners.
Commissions on each transaction.

Trading costs

When you buy or sell shares or ETFs yourself, you may pay a brokerage commission (often zero at many brokers now) plus the bid-ask spread. Currency conversion, which Canadians often pay when buying US-listed securities, can cost more than either. How brokers earn money when trades are “free” is covered in how stock brokers make money.

The arithmetic of 1% over 30 years

The US Securities and Exchange Commission’s investor bulletin How Fees and Expenses Affect Your Investment Portfolio shows a $100,000 portfolio growing at 4% a year for 20 years. With a 0.25% annual fee, it ends at about $208,000; with 0.50%, about $198,000; with 1.00%, about $179,000.

Here is a longer example. You invest $100,000 once, it earns 7% a year before fees, and you hold it for 30 years. To keep the arithmetic simple, we subtract the fee from the return each year. These are illustrative rates, not a forecast.

Annual fee	Net return	Value after 30 years	Lost to fees
0.00%	7.0%	$761,226	$0
0.20%	6.8%	$719,677	$41,549
1.00%	6.0%	$574,349	$186,877
2.00%	5.0%	$432,194	$329,032

How to read it:

A 1% fee leaves you with $574,349 ÷ $761,226 = 75.5% of the no-fee result. Roughly a quarter of the potential ending value, $186,877, goes to fees and the growth those fees would have earned.
A 2% total fee, which is easy to reach when an advisor’s fee sits on top of a fund’s MER, leaves you with about 57%.
Going from 1.00% to 0.20% keeps an extra $145,328 in this example.

The reason is compounding (see how compound growth works). Every dollar taken as a fee in year one is a dollar that never earns 30 years of returns. The fee rate looks small because it is compared with your balance. Compared with your return, it is large: a 1% fee on a 7% gross return takes about one-seventh of each year’s gain.

Layered fees add up

Fees stack. An investor might pay a 1.0% advisory fee on an account holding mutual funds with a 1.0% MER, for a total of 2.0% a year. Using the table, that is the difference between $761,226 and $432,194 on $100,000 over 30 years. Ask for the total.

What you get for the money

Fees are not automatically bad. They pay for something, and the question is whether that something is worth it to you:

Low-cost index funds buy market exposure with little else.
Active management buys an attempt to beat the market, which most funds have not managed after fees over long periods, according to S&P’s SPIVA scorecards (see active vs passive investing).
Advice can buy financial planning, tax strategy, help with registered accounts, and someone who talks you out of selling in a panic. Some people value that highly, and it can be worth more than its cost. It is worth knowing exactly what you pay for it, and whether you are actually receiving it.

Finding what you pay

US: the fee table near the front of a fund’s prospectus or summary prospectus lists loads, 12b-1 fees, and the total annual operating expense ratio. Advisors registered with the SEC must provide a Form ADV Part 2 brochure and, for retail clients, a Form CRS relationship summary describing fees.
Canada: Fund Facts and ETF Facts show the MER, TER, and any trailing commission. Dealers have had to report dollar amounts of their own fees and charges annually for years. Under the CSA’s enhanced total cost reporting rules, which took effect January 1, 2026, the annual report must also show the ongoing fund expenses you paid, in dollars, as well as each fund’s expense ratio. The first such reports cover the year ending December 31, 2026, so most Canadians will see them in early 2027.

What can go wrong

Invisible fees go unnoticed. Because MERs and expense ratios are deducted inside the fund, many investors do not know what they pay.
Comparing the wrong numbers. A fund’s MER does not include its trading costs, and neither includes an advisor’s separate fee.
Paying for advice you do not get. A trailer-paying fund held in an account where nobody advises you was a common problem in Canada before the 2022 ban, and legacy holdings may still be worth checking.
Switching costs. Selling to move to cheaper funds can trigger capital gains tax in a taxable account, or a DSC on legacy Canadian units. Look before you switch. See how stocks are taxed in Canada.
Focusing only on fees. The cheapest fund that you abandon in a downturn costs more than a slightly pricier one you stick with.

The short version

You pay for investing through fund expense ratios or MERs, sales charges, embedded trailers or 12b-1 fees, advisory fees, and trading costs. Most are a percentage of your balance, deducted quietly, and they compound: at a 7% gross return, a 1% annual fee takes about a quarter of the ending value after 30 years. Canada’s 2022 bans on DSCs and on trailers for discount-broker accounts, and its 2026 cost-reporting rules, make fees easier to see. Add up everything you pay, and know what each layer buys.