One way to choose ETFs to invest in is by comparing the options offered by your current brokerage. You should consider factors such as the total expense ratio (TER), diversity of the portfolio, prospective returns, bid-offer spreads, taxes and how long you wish to invest in the ETF. If you decide not to trade an ETF from your current brokerage, there are firms dedicated to supplying ETF trading services. However, if you're looking to trade ETFs and not pay high brokerage fees, check out our recommended online trading platforms to find the best one for you.