It's one of the largest and most rapid wealth migrations of our time: hundreds of billions of dollars, and waves of millionaires flowing out of China to overseas destinations.

According to WealthInsight, the Chinese wealthy now have about $658 billion stashed in offshore assets. Boston Consulting Group puts the number lower, at around $450 billion, but says offshore investments are expected to double in the next three years.

A study from Bain Consulting found that half of China's ultrawealthy—those with $16 million or more in wealth—now have investments overseas.

And it's not just the money that's exiting the country. The wealthy are increasingly following their money overseas.

A study by Hurun and Bank of China found that more than half of China's millionaires are considering emigrating or have already taken steps to move overseas.

(Read more: China has a word for its crass new rich)



Many experts say that the wealthy are moving to protect their wealth, their health and their families. With China increasingly cracking down on ill-gotten gains and corruption, many of the politically connected wealthy are looking for safer havens abroad.