In capitalism, wealth surges to the top but only trickles to the bottom, as was illustrated between 1870 and 1900 when a band of US industrialists became enriched beyond the realms of avarice.
Over the last 30 years, the scale of wealth enjoyed by entrepreneurs, friends and families has grown further and faster.
The multi-billion-dollar question is whether the hunger and envy that led to uprisings in late 19th century America is set to repeat itself.