Most likely the greatest disadvantage to ETFs is the fact that you have got to purchase them via a broker. Even using the low charges accessible at discount and on-line brokers nowadays, brokerage commissions can seriously erode ETFs' low-expense benefit, particularly when you are investing little sums of cash.
For instance, in the event you had been preparing to invest $100 a month in ETFs, even a price of just $10 per trade would imply 10% of one's investment is becoming siphoned off. So your ETFs' cost would need to rise 10% simply to recoup your purchasing price. And do not neglect that you will need to spend a commission whenever you sell, as well.