Index Mutual Funds vs ETFs — and TD e-Series: Which One Is Right for You?

How Does an Index Mutual Fund Work?

An index mutual fund is a passively managed fund designed to replicate the performance of a market index — for example, the S&P/TSX Composite for Canadian equities, or the S&P 500 for large-cap U.S. stocks. Instead of relying on a portfolio manager to pick winners, it simply holds the same securities as the index, in roughly the same proportions.

The defining characteristic of a traditional mutual fund is that it is not traded on a stock exchange. You place an order through the fund company, a bank, or an advisor, and the transaction is executed once per day at the fund's net asset value (NAV), calculated at market close. You invest in dollar amounts rather than purchasing a set number of shares at a fluctuating price.

This means you can invest an exact amount — say, $100 per month — without worrying about share prices, fractional units, or bid-ask spreads. The process is straightforward and lends itself naturally to automatic, recurring contributions, which is one of the most powerful habits you can build as an investor.

How Does an Index ETF Work?

An index ETF also tracks a market index passively, often at a slightly lower cost than an equivalent mutual fund. The key difference: an ETF is bought and sold on a stock exchange, just like a share of a company, throughout the trading day.

To purchase an ETF, you need a brokerage account — either a full-service or discount broker. Each purchase is for a whole number of units (unless your broker offers fractional shares), and the price fluctuates in real time. Depending on your broker, there may be a per-trade commission — though many Canadian discount brokers have now eliminated commissions on Canadian-listed ETFs — and there is always a bid-ask spread, even if it's small.

If you want to invest $75 per month in an ETF priced at $40 per unit, you can only buy one unit, leaving $35 sitting uninvested. This whole-unit constraint makes small, precise, automatic contributions more awkward unless your broker supports fractional shares.

TD e-Series Funds: A Distinct Canadian Option

This is where TD e-Series funds occupy an interesting niche in the Canadian market. Offered by TD Asset Management, these are index mutual funds — not ETFs — but with significantly lower management expense ratios (MERs) than most bank-sold mutual funds.

Their main advantages:

• Whole-dollar purchases: you invest exactly the amount you want, with no minimum unit size beyond a few dollars.
• Automatic contributions: you can set up a weekly, bi-weekly, or monthly pre-authorized purchase straight from your TD bank account — no need to log in and place an order each time.
• No per-transaction commission: unlike ETFs purchased through a brokerage, there's no trade fee.
• Accessible through a TD account: available in registered accounts (RRSP, TFSA, RESP, etc.) and non-registered accounts, without requiring a separate discount brokerage relationship — though TD Direct Investing is also an option.

The trade-off: their MERs are still modestly higher than equivalent index ETFs. The gap may feel small in early years but compounds meaningfully over long horizons. Always verify current fee figures directly from the fund's official documentation before investing.

All-in-One ETFs: A Game Changer

One development has significantly reshaped the beginner investing landscape: the rise of all-in-one ETFs (also called asset-allocation ETFs). Products like XEQT or VEQT combine multiple global indexes into a single diversified ETF, with automatic rebalancing built in.

With an all-in-one ETF, there's no need to manage multiple funds or rebalance manually. One ticker, global diversification, very low fees. For someone who has a commission-free discount brokerage account and contributes amounts large enough that the whole-unit constraint isn't a problem, this is often the most elegant solution available.

But for a beginner starting with small amounts who wants to automate without friction, the index mutual fund — and TD e-Series in particular — remains a genuinely useful tool.

Which Option Suits Whom?

Here's a practical framework for thinking through the choice:

• You're just starting out with small contribution amounts (under $500 per deposit) and want to automate without logging in each time → an index mutual fund like TD e-Series can reduce friction and help you stay consistent.
• You already have a discount brokerage account and are contributing larger amounts → an all-in-one ETF like XEQT or VGRO is often advantageous thanks to slightly lower fees.
• You want the flexibility to trade intraday → only ETFs offer that.
• You're choosing between the two based primarily on cost → compare the current MERs of the specific products you're considering. The gap varies by fund family and changes over time; always check the official fund documents.

Ultimately, the best investment is the one you stick with through market ups and downs. A slightly less optimized strategy you follow consistently will almost always outperform a theoretically perfect strategy you abandon at the first sign of volatility.

Frequently asked questions