Many companies offer index funds and ETFs. If two funds or ETFs track the same fund, what differentiates the two? Is it common for one index fund to outperform another? How can this happen if the funds/ETFs are tracking the same index?
I found this post comparing index funds and ETFsthis post comparing index funds and ETFs. When forced to choose between them, index ETFs look like the better option (under the right circumstances), but what differentiates index funds/ETFs when compared to similar vehicles?