Christine Lagarde, managing director of the International Monetary Fund (IMF), has warned that the US' failure to raise its debt ceiling could be far worse than the country's current government shutdown.
Fears over US monetary tightening, rate hikes, and recession triggered the 1987 stock market crash, and there are parallels with today's market environment, according to Société Générale's Albert Edwards.
European financials are among the day's biggest fallers as benchmark French and German indices struggle amid intensifying geopolitical concerns.
Investors should be thinking about cutting their exposure to Asia and emerging markets and looking more to the developed world, according to F&C co-head of multi-manager Gary Potter.
Big moves in the technology and materials sectors helped the S&P 500 close at its highest ever level on Monday.
The US' three major equity markets dropped overnight after a bomb blast at the Boston Marathon shook markets and weak data from China continued to weigh on stocks.
Global markets soared on Wednesday after the US Federal Reserve inadvertently released minutes from its latest policy meeting five hours earlier than planned.
The S&P 500 is on the verge of passing its all-time closing high after rising as much as 0.5% in early trading.
Cherry Reynard examines whether the global equity rally can be sustained...