Butterfield Bank dropped 3.07 percent (four cents) on The Bermuda Stock Exchange (BSX) yesterday.The bank traded 10,000 shares to close at $1.28.KeyTech Ltd also fell 0.82 percent (five cents) to $6 as 1,200 shares changed hands.The Index, as a whole, slipped 19.76 points (1.73 percent) to 1,123.69 with 11,200 shares worth $19,800 transacted.The BSX Insurance Index rose 19 points (1.92 percent) to 1,008.