How markets could topple the global economy

IF AMERICA’S stock market were to crash, it would be one of the most predicted financial implosions in history.

Everyone from bank bosses to the International Monetary Fund has warned about the stratospheric valuations of US tech companies. Central bankers are bracing for financial trouble; investors who made their names betting against subprime mortgage bonds in the 2007-to-2009 period have resurfaced for another “big short”.

At any sign of a wobble, such as a recent slight weekly fall in the Nasdaq index of tech stocks, speculation mounts that the market is on the precipice.