The decline is the first time global household wealth has fallen since the economic crisis of 2007-2008, but when stripping out currency headwinds the underlying trend points to net worth growing every year this century, apart from the financial crisis period, the report found.
This dip in overall wealth also hit the number of millionaires, which having climbed from 13.7 million at the turn of the century to 36.1 million in 2014, fell back this year to 33.7 million due to exchange rate effects.
"The rise of 146 percent (in millionaires) since 2000 reflects population growth and the fact that inflation progressively lowers the bar for membership of the millionaire club. Nevertheless, the number of millionaires has still grown significantly after discounting for these factors," the report authors said.
The U.S. tops the list of countries with wealth rises again, with an increase of $4.6 trillion, falling way short of the $9 billion gained the year before but "substantial" in the global context, according to Credit Suisse.