Argus Group Holdings Ltd was the biggest loser on the Bermuda Stock Exchange (BSX) last week.The insurer dropped 9.6 percent (48 cents) to $4.50 with 1,715 shares traded.Fellow insurance company BF&M Ltd also fell 2.7 percent (40 cents) to $14.60 as 200 shares changed hands.Meanwhile Butterfield bank slipped 2.2 percent (three cents) to $1.34 with 335,130 common shares transacted.The bank also traded 39 preference shares, but its share price held firm at $1,250.But the Ascendant Group Ltd rose 0.4 percent (five cents) to $14.05 as 31,300 shares changed hands.Other traders included Bermuda Press (Holdings) Ltd which transacted 700 shares, but its share value remained unchanged at $11, and KeyTech Ltd which traded 242 shares, but held firm at $6.Overall the Index dipped 25 points (2.15 percent) to 1,160.47 with 369,287 shares worth BD$901,225.65 and 8,340 shares worth US$136,055.40 changing hands.The BSX Insurance Index, however, climbed 12 points (1.17 percent) to 1,011.