Argus Group Holdings Ltd was the biggest climber on the Bermuda Stock Exchange last week, gaining more than five percent.The insurer and investment company rose 25 cents, or 5.5 percent, to close on $4.75 as 27,280 of its shares changed hands.It was not such a good week for Bermuda Aviation Services Ltd, however, as the company’s shares fell 19.2 percent, or 95 cents, to close the week on $4, after 2,000 shares traded.Butterfield Bank managed a gain of one cent, or 0.7 percent, to $1.39, as more than 54,000 of its shares were traded over the five days.Ascendant Group Ltd also saw significant trading activity, but remained unchanged on $14.05 as 20,262 shares were exchanged.The Royal Gazette / BSX Index gained 9.59 points, or 0.8 percent over the week, to close on 1,190.65.Volume was 108,266 shares and turnover totalled $558,411.90.