An influx of ultra-wealthy business tycoons from India has helped to cement Dubai as the city in the Middle East with the most billionaires.
The emirate is now home to the highest concentration of billionaires in the region - there are 14 of them - and ranks 18th globally.
Since 2007, the average per-capita wealth of billionaires residing in the UAE has dropped 10 per cent, though the number of billionaires has doubled, according to data from WealthInsight, which analysed more than 1,300 billionaires.
"As expected, the UAE has a number of foreign national billionaires in the country, coming from countries including Bahrain, India, New Zealand, Pakistan and Saudi Arabia," said Stephen Gross, a senior analyst in the London office of WealthInsight.
But the company said Dubai's position might be "undermined" by Singapore, which took 19th spot to become the biggest contender against the emirate going forward.
"In terms of competition with Dubai, it has more to do with the Indian business," said Mr Gross. "There's a lot of Indians who are not residents in India, and those are the ones that Dubai and Singapore are both competing for."
Both locations are also courting billionaires seeking a haven from having to pay taxes, particularly after scrutiny increased over accounts in Switzerland. Dubai could benefit from wealthier individuals coming into the emirate following the Arab Spring, and if more unrest in the region continues - but there had not been such an effect among billionaires as of yet, Mr Gross said.
Singapore stands to gain the most from a growing group of billionaires who hail from China, which has five cities in the top 25, including Shanghai in 8th spot.
Besides Dubai, two other Middle Eastern cities - Jeddah and Riyadh - also made it into WealthInsight's top 25 ranking.
Istanbul, which is considered neither a part of the Middle East or Europe by WealthInsight, took sixth spot, ahead of San Francisco but just behind Mumbai.
Globally, however, more developed cities and those within the US and Europe tended to reign supreme in terms of the concentration of billionaires. New York City came out on top, followed by Moscow, London and Hong Kong.
The lower part of WealthInsight's ranking illustrates the growing rivalry between cities such as Riyadh, which ranked 24th, and booming places within China, such as Hangzhou, which was 25th.
"We are likely to see much change to this list in the year ahead as the Saudi Arabian duo are contested by China's Hangzhou and [other] second-tier cities such as Jinjiang in Fujian province, which lurks in the shadows in 26th place," said Karishma Gupta, an analyst with WealthInsight.
