The US Nasdaq index has closed above its dotcom boom record for the first time in 15 years.
A UK financial trader has been arrested over claims by the US that he helped cause the 2010 Wall Street "flash crash".
Mixed fortunes flummox investors in Sterling Strategic Bonds
Ian Aylward has cut Aviva Investors' multi-manager exposure to US equities to an underweight position for the first time since 2011, fearing the stocks are deeply over valued.
The global economy is set to grow slower this year and next, according to the International Monetary Fund (IMF).
The World Bank has cut its global growth forecast, warning the US alone cannot drive an economic recovery.
As the US Federal Reserve finally turns off the money printing presses, veteran investor Bill Gross has warned the global economy cannot survive without the support of quantitative easing.
The Bank of International Settlements (BIS) has warned of a potentially 'violent' market crash as financial markets are dangerously stretched.
Shares on Wall Street have recorded the worst three-day streak since 2011 after another sharp move lower overnight, with investors continuing to fret over the end of the US Federal Reserve's bond buying programme.