Janet Yellen used to be undecided but now she's not so sure. The head of the US Federal Reserve has vacillated for the last two months about when American interest rates will finally be increased for the first time since 2006, and in the process has added further uncertainty to global stock markets - already spooked by signs of weakness in the Chinese economy and the recent rout in emerging markets.

Earlier in the year markets were getting an 'attack of the vapours' at the thought of any rate increase in case the global recovery was stalled by it, but now they're in a flap in case the Fed's reluctance to do so now indicates that they believe that that recovery is failing anyway. Talk about inconsistencies.

The market's worries were succinctly expressed by Bill Strazzullo, chief strategist at market research firm Bell Curve Trading, who said: "If growth in the strongest economy, the United States, isn't strong enough to raise rates even a quarter of a point, what does that say about the prospects for global growth?"

Realistically moving interest rates in fractions around zero is likely to have little real economic effect, but the reality is that nearly a decade of minimal rates have made any increase more of a psychological issue rather than a monetary one with the Fed and the Bank of England anxiously hoping the other will make the first move on raising rates.

With so much (largely unnecessary) uncertainty we don't see a quick end to the current market volatility, which leaves investors in a quandary, particularly those who are relatively close to needing their money.

In the last few weeks we've seen a significant flight into the developing area of guaranteed investments as people seek to ensure that they keep hold of what they've already accumulated while still having a greater growth potential than the appalling rates of interest on cash deposits which are unlikely to improve anytime soon.

Robin Sainty APFS M.A. (Cantab)