Butterfield Bank’s preference shares dropped 1.2 percent ($15) on The Bermuda Stock Exchange (BSX) yesterday.The bank traded 80 shares to close at 1,235. It also saw 49,600 common shares change hands, but its share value held firm at $1.50.Argus Group Holdings Ltd also fell .2 percent (one cent) to $4.99 with 300 shares transacted.Fellow insurer BF&M Ltd traded 19,926 shares but its share price remained unchanged at $15.The Ascendant Group Ltd also saw 4,500 shares change hands as its share value opened and closed at $14.Overall the Royal Gazette/Bermuda Stoc Index slipped 0.18 points (0.01 percent) to 1,231.57.The BSX Insurance Index, however, rose 40 points (4.51 percent) to 927.