The survey, from the Boston Consulting Group, also showed Qatar, Kuwait and the UAE were among the top 10 countries worldwide on the number of millionaires per capita.
One in every 20 UAE households has more than $1m in assets, compared with one in every 11 households in Qatar.
…But these Gulf states are dwarfed in wealth by Saudi Arabia.
The kingdom emerged as the leading country in the world for ultra-high-net-worth households, defined as those with a net worth of more than $100m, with 18 such families for every 100,000. Switzerland came second, with 10 such households for every 100,000.