Traders will be glad to see the back of 2018. Nearly $7 trillion has been wiped off world stocks, emerging markets have been trampled flat by a charging dollar and even gold and U.S. government bonds have lost money.

A grisly combination of U.S.-China trade tensions, central banks turning off the money taps and cooling growth in former hot spots has wiped 10 percent off MSCI's 47-country world stocks index — its first double-digit loss in any year since the 2008 global financial crisis.

Many places have fared far worse. Top Chinese shares have fallen 25 percent into "bear" territory, export bellwether Germany has shed 16 percent, and Turkey and Argentina have led emerging markets losses, down 45 and 50 percent, respectively.