I hold my bitcoins online at Coinbase. Even seems not secure in the first view this is only an impression and not a fact. Seems that the online wallet are the less secure but if read all the data given about this matter offered by Coin base understand the right meaning that the word "secure" has for this business. I am writing some. First must be told (even this has nothing to do with the security but with your pocket) all the fee-s of the sent of bitcoin are paid from Coin base.