World Markets Update: Substantial Global Selloff

 | Dec 13, 2015 12:41AM ET

All eight indexes on our world markets watch list suffered weekly losses. In fact, the average of the eight was -3.18%, the worst collective performance since the first week in September. Japan's Nikkei 225 had the best week, down only -1.40%. The UK's FTSE 100 had the worst week, down -4.58%.

Here is an overlay of the eight for a sense of their comparative performance so far in 2015.