Chris Redfern Moneycorp

After a couple of weeks fretting vaguely about the popup cold war over Crimea, investors were relieved last Monday when the EC and the United States announced their sanctions against Russia.

Travel bans and assets freezes for a couple of dozen civil servants and politicians appeared to be no threat to the global economy, so investors swung back towards 'riskier' investments and currencies.

As was the case the previous week, that swing was anything but coherent. The safe-haven Swiss franc and Japanese yen took only glancing blows. The two northern Scandinavian crowns headed in opposite directions. The commodity-oriented Australian dollar led the field while the commodity-oriented South African rand went to the bottom of the ladder.

Investors found it difficult to find inspiration among the economic data so it was left to central bank chiefs to provide it. The Bank of England's Mark Carney did his bit to depress the pound, saying that low interest rates 'will likely be with us for some time'. Later the same day Stephen Poloz at the Bank of Canada made a similar comment, sending the Loonie lower.

But the most effective piece of verbal intervention came from Janet Yellen at the Federal Reserve. During her first press conference Ms Yellen allowed investors to believe that the money-printing stimulus will continue to be reduced by $10bn a month and that US interest rates will begin to head higher 'around six months' after the taper is complete. That means in the first half of next year so it is game on again for the US dollar.

Sterling had a fairly smooth ride, helped by decent employment data and upgrades to the UK economic outlook. It will face more challenges in the coming week with figures for inflation, house prices, retail sales and finalised fourth-quarter growth all threatening to trip it up.