A robust performance by a handful of our top tips helped us to minimise losses last week when the stock market suffered a bout of jitters over the American economy.

Scottish tech minnow Optos caught the eye, with further support taking its share price gain to more than 10% over the past fortnight, while Edinburgh's John Menzies and Perth-based Stagecoach also gained ground. Royal Mail joined the winners as the shares shrugged off the effects of profit-taking by small investors to stage a strong rally just as we were preparing to sell under our stop/loss rules.

Our 2013 portfolio was the main beneficiary with its total valuation up just more than 2% over the week when we carried out our usual review on Wednesday morning.

Other selections fared less well, though the 2010 portfolio suffered only a fractional slippage as the Menzies share price increase helped to cancel out losses elsewhere and it remains firmly on course to record gains of more than 100% when it is liquidated at the end of the month.

In contrast, the 2011 list saw its total valuation slump by more than 3% after catering giant Compass went into sharp reverse despite its recent encouraging trading statement and B&Q retailer Kingfisher fell back on concerns over prospects for the general retail market this Christmas. The share price has now dropped nearly 10% from previous highs.

The 2012 selections went into reverse to show an overall loss of around 1.5% on Wednesday after showing some good gains earlier in the week as profit-takers moved in on Belhaven Brewery group Greene King after it announced a surprise boost to its dividend payments.

Coal-fired power station Drax slipped on concerns over subsidy cuts expected in its drive to increase biomass power generation.