The ideal index fund would deliver the precise return of its benchmark, but we all know that’s not realistic. ETFs and index funds may be cheap but they’re not free, and fees almost always cause them to lag slightly. Index investors accept this because they know the alternatives are usually much worse, but they can’t be too complacent. It’s important to periodically check your ETF’s tracking error: that is, the difference between the index return and the fund’s actual performance.
Where do you find this information? Over at iShares, you simply visit the ETF’s web page and click the “Performance” tab. You’ll see the returns of both the fund and its index over various periods from one month to 10 years, as well as calendar-year returns. iShares currently lists fund returns according to net asset value (NAV) only: the market price field is blank. For example, over the 12 months ending March 31 the iShares S&P/TSX Capped Composite (XIC) lagged its index by 29 basis points:
The process is almost identical at Vanguard: again, simply visit the ETF’s web page and click the “Performance” tab.