Telecommunications group KeyTech Ltd was the biggest climber on the Bermuda Stock Exchange yesterday, climbing 8.5 percent.But The Royal Gazette / BSX Index fell 15.08 points, or 1.3 percent, to 1,151.34 after Butterfield Bank’s share price tumbled 3.8 percent.KeyTech rose 54 cents to $6.90 on the trading of 393 shares. Butterfield fell five cents to $1.25, as 12,056 shares changed hands.Bermuda Commercial Bank Ltd had a positive day, rising 15 cents, or 1.5 percent, to $10, its highest close since last July, as 650 shares traded.Argus Group Holdings Ltd edged five cents, or 0.9 percent higher, to $5.80, in the week the insurer announced Alison Hill would take over as CEO from Gerald Simons, who will remain in the role of company president. 1,920 Argus shares were exchanged.Rival insurer BF&M Ltd remained unchanged on $14, as 2,500 of its shares changed hands.Ascendant Group ltd, owner of electricity company Belco, moved upwards five cents, or 0.3 percent, to close on $15, as 200 shares traded.BSX trading volume was 17,719 shares and turnover was $73,344.75.The BSX Insurance Index fell six points, or 0.6 percent, to 1,019.