Stock markets have rallied since the end of June and many investors are eagerly expecting further central banking stimulus in the US and Europe, but Coutts warns that events in the coming months could send markets lower.

The wealth arm of Royal Bank of Scotland says that it seems as if investors have priced in a let-up in the challenges facing Europe as well as an easing of growth concerns in the rest of the world.

"Many equity markets are at or close to their year’s highs and technical indicators highlight tactical risks to markets," the UK firm says.

The key risk events will begin on 31 August, with US Federal Reserve chairman Ben Bernanke’s speech at the central bankers’ conference at Jackson Hole, Wy, followed the day after with a speech by the European Central Bank president, Mario Draghi.

Coutts has thus adopted a tactical cautious short-term view on equities, based on the combination of technical indicators and the challenges policy-makers face in providing more stimulus.

On the long-term, however, the firm sees plenty of reasons to invest in stocks, such as attractive valuations, strong corporate earnings and continued easy monetary policy.

Coutts is also interested in other risk assets that it expects will be more resilient during periods of crisis, for example income-oriented classes such as high-yield, emerging market and investment-grade bonds.