Shares of Somers Group Ltd surged 25 per cent on light trading on the Bermuda Stock Exchange.The financial-services holding company added $3 to jump to $15 as 300 shares changed hands.Somers, which has received the go-ahead from regulators for its sale of Bermuda Commercial Bank, was the only stock to trade on the BSX.The Royal Gazette/BSX Index gained 19.95 points, or 1.13 per cent, to close on 1,791.25.The BSX Insurance Index plummeted 80.08 points, or 5.15 per cent, to close on 1,475.94.Butterfield Bank’s US-listed shares fell 84 cents, or 3.81 per cent, to close at $21.22 on the New York Stock Exchange. The bank last traded on the BSX at $24.