MER stands for management expense ratio, which is an annual fee that covers the fund’s operating expenses. The MER is comprised of several expenses like legal fees, taxes, management fees, and administrative costs. The cost of the MER does not have any impact on how the fund will perform, meaning a low MER doesn’t guarantee great returns, whereas a high MER doesn’t mean worse performance. MER fees matter more over the long term and should only be one thing that is analyzed when you are deciding which ETFs the best addition to your portfolio.