Butterfield Bank shares dropped on the Bermuda Stock Exchange yesterday.Some 32,625 of the Bank’s shares traded hands, closing down 5.2 percent, at $1.28.Twenty BF&M shares were exchanged, closing unchanged at $14.90.Overall the BSX closed down 33.27 or 2.83 percent, at 1,141.06.The BSX Insurance Index closed down 2.00 or 0.22 percent at 905.00.