추적오차(Tracking Error)란 무엇인가요?

인덱스 펀드가 지수를 얼마나 정밀하게 추종하는지, 그리고 괴리가 발생하는 이유.

An index ETF's job is to match its index. Tracking difference is the gap between the fund's return and the index's return over a period; tracking error, strictly, is the volatility of that gap. Both measure execution quality.

Gaps come from the expense ratio (a constant drag), trading costs when the index changes, cash held for distributions, securities-lending income (which can offset costs), and, for international funds, taxes withheld on foreign dividends.

A well-run large index fund typically lags its index by roughly its expense ratio. A fund that lags by much more than its fee — or that swings around the index — deserves a closer look at how it is managed.