Bermuda Commercial Bank dropped 50 cents (4.76 percent) on the Bermuda Stock Exchange yesterday, trading 200 shares to close at $10.Butterfield Bank gained one cent (.81 percent), trading 3,660 shares to close at $1.24.Overall, the BSX closed at 1,065.26, up 1.74 points (.16 percent), trading 3,860 shares worth $6,509.80.