The ranks of the world's super-rich have been shredded by the credit crunch, undermining the theory that the wealthy are better at holding on to their money.

The global population of "ultra high net worth individuals" - defined as those with at least $30m (£18m) to invest - shrank by nearly 25 per cent in 2008 to 78,000, according to the latest World Wealth Report produced by Merrill Lynch and Capgemini. The collective net wealth of these super-rich slumped by 24 per cent after a year of bank crises, government bail-outs and stock market routs.