Butterfield Bank shares gained 1.5 percent to boost The Royal Gazette / Bermuda Stock Exchange (BSX) Index yesterday.The bank’s common shares finished the day two cents higher at $1.24, as 8,000 shares changed hands.There was busy trading in Butterfield’s preference shares, which have an annualised yield of eight percent. The shares gained $11 to close at $1,231, as 228 shares were traded.The only other domestic-board issuers to trade were Ascendant Group Ltd, which remained unchanged on $12.10, and BF&M Ltd, which was unchanged at $16.The index rose 9.48 points, or 0.89 percent, to close the day’s trading on 1,075.57. Volume totalled 9,277 shares and turnover topped $306,000.