The Basel-based institution, considered the central bank for central banks, also voiced concern in its quarterly report about the impact of the rising US dollar and falling oil prices, particularly on emerging economies.

Claudio Borio, the head of the BIS monetary and economic department, highlighted events in mid-October when stock prices fell sharply and US Treasury bonds were “exceptionally volatile” — even more than at the height of the crisis triggered by the collapse of Lehman Brothers in 2008.

“And yet, just a few days later, the previous apparent calm had returned.

“To my mind, these events underline the fragility — dare I say growing fragility — hidden beneath the markets’ buoyancy,” he said.

Global stocks are surging on hopes that the world’s biggest economy is recovering, with a surprisingly robust US jobs report for November powering Wall Street to record highs last week.

The dollar has also strengthened against the euro and the yen, as the central banks of the single European currency zone and Japan push interest rates to record lows to chase an elusive growth.

At the same time, oil prices have slumped by 40 per cent since June because of oversupply — the third largest fall in the last 50 years.

Mr Borio said the diverging developments were expected to “leave a profound imprint on the financial and macroeconomic scene”.

Emerging market economies expected to be hardest hit because “the out-size role that commodities and international currencies play there makes them particularly sensitive to the shifting conditions,” he said.

Emerging economies have racked up to $US3.1 trillion ($3.4 trillion) in dollar-denominated debt by mid-2014.

A continued appreciation of the dollar would therefore increase debt burdens, Mr Borio said.