I really liked the commission free ETF setup at Fidelity because they offered two of the really liquid ones (IWM and EEM) with great option depth. Unfortunately, they partnered up with Blackrock and swapped 10 ETF, thereby dropping IWM and EEM. The replacements are IJR and IEMG (dropping volumes from about 17M to a whopping 50-100k, with worthless option chains). They also now charge a short term trading fee if you sell the commission free ETF within 30 days of purchase. There is a grace period to sell existing positions in those ETF without commission until the end of May. Just an FYI in case you were unaware.