Monaghan-born White emigrated to the United States where he made his fortune from direct marketing. He set up Abacus Direct in 1990 and floated it seven years later on the Nasdaq. Two years later, he netted 63m in stock when he sold the business to internet ad broker, DoubleClick, for 1.05bn.
Since then there have been some extremely profitable Manhattan property plays. The Trinity graduate sold a house at 118 East 70th Street to Woody Allen for 22.8m in 2006. He then doubled his money on another townhouse, selling it three years ago for 31.6m.