Net worth: $30.6 billion

Age: 88

Country: Hong Kong

Industry: Diversified investments

Source of wealth: Self-made; CK Hutchison Holdings

Despite humble beginnings, business magnate Li Ka-shing has become the wealthiest man in Hong Kong. After his father died of tuberculosis, Li dropped out of school at 16 to support his family, working in a factory making plastic flowers. Six years later, he opened his own factory, the predecessor to what's known today as CK Hutchison Holdings, a vast business empire with interests in real estate, manufacturing, energy, telecommunications, and technology.

A savvy investor, Li and his venture-capital fund Horizon Ventures have backed companies like Facebook, Skype, Spotify, and the egg-replacement food startup Hampton Creek.

Two years ago, Li reorganized his business affairs under two new listed companies, one entity for property holdings and another for all other global assets. The move is most likely in preparation to hand over control of his sprawling fortune to his son, but the 88-year-old doesn't have any plans of slowing down just yet. In August 2015, he opened the 12,000th location of AS Watson, CK Hutchison's health and beauty-products retailer, now the largest in the world. Li's net worth rose by $4.1 billion over the past year.