Just looked into which cities actually have the most millionaires and billionaires worldwide, and the concentration is pretty wild. Turns out the richest city in the world when you count by sheer number of ultra-wealthy residents isn't where most people think.

New York absolutely dominates with nearly 350,000 millionaires and 60 billionaires. Bay Area comes in second with over 305,000 millionaires but actually has more billionaires at 68. Tokyo's third with around 298,000 millionaires, though interestingly it lost about 5% of its millionaire population between 2013 and 2023.

What's fascinating is the growth patterns. Beijing saw millionaire population jump 90% over that decade, while London and Hong Kong both dropped around 10%. Singapore and Paris are also in the top 10 but with slower growth. Sydney, Hong Kong, and Beijing round out the list, each with between 125k and 147k millionaires.

So when people ask what the richest city in the world is by concentration of wealth, it really depends on the metric. By absolute numbers, New York and Bay Area are untouchable. But by growth trajectory, some Asian cities are catching up fast. The wealth distribution across these cities tells you a lot about where capital is actually flowing these days.