Shares of Butterfield Bank improved by $1.75, or 6.9 per cent, to $27 after 550 traded on The Royal Gazette/BSX Index.On the New York Stock Exchange the bank’s shares were up seven cents, or 0.26 per cent, at $27.02.The Royal Gazette/BSX Index was up 78.71 points, or 4.29 per cent, at 1,912.68, while the BSX Insurance Index was up 1.15 points, or 0.08 per cent, at 1,506.98.