A bank is not really a viable option for a collector. Access to your collection is way too limited, and only OK if you are travelling for an extended period, as I once did, for a couple of years.
I have a small safe, and my collection is very active. Only my most valuable coins are stored in the safe, and the rest of the collection is studied on a daily basis. A small bag of silica gel in the safe seems to help. Most of my most valuable coins are in acryllic screw capsules anyway.
Even ancients can be stored in this way.