Fears of growth in the U.S. have also weighed on markets, according to analysts, pushing investors into traditional safe haven assets, such as gold and U.S. Treasurys. Gold prices hit a three-month high on Monday, extending their largest weekly gain since July 2013, rising to $1,182.
The yield on the 10-year Treasury notes, which moves inversely to the bond's price, dipped further below 2 percent at 1.804 percent, after closing at 1.848 percent on Friday. This is down from 2.3 percent at the start of the year, as safe-haven buying has continued to weigh on yields.
In commodity markets, crude prices traded down, hovering around $30 per barrel as traders held out little hope a meeting between OPEC producers Saudi Arabia and Venezuela would result in any change in output levels.
Investors will be keen to hear what Federal Reserve Chair Janet Yellen has to say this week as she delivers two days of testimony on the economy before congressional committees Wednesday and Thursday. The Fed chair's testimony comes as markets grow anxious about the health of the economy and the Fed's stated intention to continue hiking rates.