Gambling Man is the biography of one of the world's least known but most consequential investors.

Japan's Masayoshi Son has made and lost several fortunes, investing or controlling assets worth $1 trillion in the past two decades through his media-tech giant, SoftBank. He bankrolled Alibaba, China's internet colossus, before the world had heard about it; plotted with Steve Jobs to turn the iPhone into a wonder product; and financed hundreds of tech start-ups, fuelling the biggest boom Silicon Valley has ever seen.

This book takes you on Son's wild ride, from his birthplace in a Korean slum in post-war Japan to the modern-day temples of power. It speeds through Donald Trump's golden skyscraper in Manhattan, the royal palaces of Riyadh and the throne rooms of China's Marxist rulers; all places where Son has deployed his unique blend of financial engineering and crazy risk-taking.

Son's story captures a 25 year-span of hyper-globalisation in which money, technologies and ideas flowed freely. From the launch of the microchip to the advent of artificial intelligence, he has ridden the technological wave which has created extraordinary wealth and economic change. His topsy-turvy business career is testimony to the power of optimism, daring to dream, ever in search of the Next Big Thing.

As an ethnic Korean in Japan, Son has overcome adversity and discrimination to become Japan's best-known businessman and empire-builder but he remains an elusive, intensely private figure. This book, by a former editor of the Financial Times, contains a wealth of new information and has had the co-operation of many of the key participants, including Son himself. Written with a verve appropriate to its subject, Gambling Man reveals the man behind the money, what drives him, why he matters, and what he plans for his next act.