Local stocks gained last week in light trading.The Royal Gazette / Bermuda Stock Exchange (BSX) Index gained 15.5 points, or 1.37 percent, to close the week on 1,130.99.The main driver of the rise was the 1.6 percent increase in the share price of Butterfield Bank. The bank gained two cents over the five days to end Friday on $1.28.The majority of turnover in last week’s trading was generated by Butterfield’s preference shares, which fell $11, or 0.9 percent, to $1,225 on the trading of 1,033 shares.The biggest climber was Bermuda Aviation Services Ltd, which rocketed 22.2 percent on the trading of just 100 shares, as it gained 90 cents to close on $4.95.Ascendant Group was another climber, adding 24 cents, or 1.7 percent, to finish the week on $14.25, as 1,030 of its shares changed hands.Volume for the week was just over 13,200 shares and turnover totalled BD$27,435 and US$1.28 million.