Equal-Weight vs Cap-Weighted ETFs: Understanding the Difference for Canadian Investors

What Is a Cap-Weighted ETF?

In a cap-weighted (market-capitalization-weighted) ETF, each holding takes up a share of the fund proportional to its total market value. The bigger a company’s market cap, the larger its slice of the pie. This is the methodology used by the vast majority of popular index ETFs, including the iShares Core S&P/TSX Capped Composite (XIC) for Canadian equities and the Vanguard S&P 500 (VFV) for U.S. exposure.

The result: a handful of mega-caps dominate. In the S&P 500, the top ten companies have regularly accounted for more than 30% of the entire index. In Canada, the S&P/TSX Composite is notably concentrated in financials and energy — the Big Six banks alone carry substantial weight. To understand how this calculation works, check out our article on market capitalization.

What Is an Equal-Weight ETF?

An equal-weight ETF allocates roughly the same percentage to every constituent in the index, regardless of company size. If the index holds 100 companies, each gets approximately 1% of the fund. A small mining company carries the same weight as a major bank.

This approach gives a much larger voice to mid- and small-cap names. It also creates a natural tilt toward smaller companies and value stocks, since high-growth companies that rapidly increase their market cap get trimmed back at every rebalancing date. To understand what small-cap investing means in practice, see our article on small-cap vs large-cap investing.

Side-by-Side Comparison

Source: TMX Group and public ETF provider data.

The Canadian Angle: TSX Sector Concentration

The S&P/TSX Composite is famously concentrated. Financials and energy together often represent more than half the index by weight. If you hold a plain-vanilla Canadian index ETF like XIC, you are heavily exposed to banks, insurers, and oil producers — whether you intend to be or not.

An equal-weight approach on a Canadian index redistributes that exposure, giving proportionally more room to underrepresented sectors like technology, health care, and materials. For investors who feel the TSX is too top-heavy, equal-weighting can offer more meaningful sector diversification.

That said, if mega-cap financials outperform — which often happens during rising-rate cycles — the equal-weight version may lag. For more on how index composition works, see our piece on what a stock index is.

Why Does Equal-Weighting Cost More?

Maintaining equal weights requires regular rebalancing. Every quarter (or semi-annually), the fund manager must sell holdings that have risen in value and buy back those that have fallen, to restore the equal-weight targets. This higher turnover generates transaction costs and additional management work.

As a result, equal-weight ETFs typically carry a higher MER than their cap-weighted equivalents. That is not a reason to automatically avoid them, but it is a real cost to factor into your decision. GetSmarterAboutMoney.ca — operated by Canadian securities regulators including the OSC and provincial securities regulator — recommends comparing MERs carefully before selecting any ETF.

Which One Performs Better?

The honest answer: it depends on the market environment and time horizon. Over long periods, research has suggested equal-weighting can modestly outperform, partly because of its exposure to the small-cap and value factors — two factors that have historically earned a return premium. But during bull markets driven by a few large-cap tech giants (as seen from 2019 to 2021), cap-weighted funds often came out ahead.

The key is recognizing that each approach represents a different bet on which parts of the market will lead. If you hold multiple ETFs and want to check how much overlap exists between them, our article on ETF overlap is a useful next read.

Frequently asked questions