US stocks fell slightly after violent swings in both directions last week, and investors are strapping in for more of the same this week.

If the bulls are to gain the upper hand, earnings growth will have to continue outstripping Wall Street estimates. For the bears, there is always the chance of another spike in Treasury yields or a shock from Washington.

The cross currents last week were almost bewildering: the Federal Reserve's decision not to hike interest rates came a few hours before the latest furore in the matter of US President Donald Trump versus porn star Stormy Daniels.