Global financial markets traditionally take their cue from the United States. Unexpected Fed rate hikes have unsettled global markets in the past. The entire global financial system threw a tantrum when then Fed Chairman Ben Bernanke merely suggested in May 2013 that the end to bond-buying and other policies could soon begin. However for the past year, the gears of global markets seem to have been thrown into reverse — it is German government bonds, known as Bunds, rather than U.S. bonds, known as Treasuries, that appear to be driving prices in global bond markets. This role reversal could add a new layer of complexity to investor calculations as they prepare for the beginning of Fed interest rate hikes, which are expected later in 2015. Also, as developments in Greece lead to rises and falls in Bund and Treasury yields, this is a trend worth keeping an eye on.