Billionaires on average became poorer last year as their collective fortunes shrank, even as Asia continued to crank out a new billionaire nearly every three days.

Transfers of assets within families, falling commodity prices and a stronger dollar helped reduce total billionaire wealth by $300-billion (R4.3-trillion) in 2015 to $5.1 trillion (R72.7-trillion), a study released yesterday found.

The average billionaire - 1397 of them - was worth $3.7-billion, the survey of 14 big markets by Swiss wealth manager UBS and advisory group PwC discovered.

"After more than 20 years of unprecedented wealth creation, the Second Gilded Age has stalled."

The US added only five billionaires as 41 joined and 36 dropped out of the ranks of the ultra-rich. China minted 80 new billionaires.

In Europe, old money is especially adept at passing wealth down the generations. Germany and Switzerland had the most . Two decades of unparalleled fortune generation are about to make way for the greatest wealth transfer in history, the study found.