Some funds may have the same investment goal. But still they have management costs that can vary wildly. These costs may not seem like a big deal in the short term because they are pretty low but in the long-term investment returns can take a massive hit from the smallest fee inflation. However the thing with big funds is that they have lower fees.
The main costs to keep in mind about index fund are:
1) Account minimum
A brokerage’s account cost may be $0 but that does not remove the investment minimum for a particular index fund.
2) Investment minimum
This one is about the minimum required to invest in a mutual fund can run as high as a few thousand dollars.
3) Expense ratio
This one are main costs of subtracted from each fund shareholder’s returns as a percentage of their overall investment.
4) Tax-cost ratio
This the last one to keep in mind. And this one is the addition to paying fees which is all about owning the fund may trigger capital gains taxes if held outside tax-advantaged accounts just as IRA or 401(k)