Billionaires have seen their combined wealth shoot up 121 percent over the past decade to $14 trillion, Swiss bank UBS said Thursday.

Switzerland's biggest bank said the number of dollar billionaires increased from 1,757 to 2,682 over past 10 years.

The 10th edition of UBS's annual Billionaire Ambitions report found that billionaires have comfortably outperformed global equity markets over the past decade. The report documents "the growth and investment of great wealth, as well as how it's being preserved for future generations and used to have a positive effect on society", said Benjamin Cavalli, head of strategic clients at UBS global wealth management.