Masayoshi Son (, ) (born 11 August 1957) is a Japanese billionaire technology entrepreneur, investor and philanthropist. A 3rd generation "Zainichi Korean", he naturalized as a Japanese citizen in 1990. He is the founder, chairman and chief executive officer (CEO) of the Japanese holding company SoftBank, CEO of SoftBank Mobile and chairman of UK-based Arm Holdings. Since Son founded SoftBank in 1981, he has made many investments, but the vast majority of those deals failed, and his reputation as an investor rests almost solely on his $20 million investment in Alibaba Group in 2000, a stake that was worth $130 billion in 2018. The morphing of his own telecom company SoftBank Corp. into an investment management firm called SoftBank Group Corp. made him noted worldwide as a stock investor. However, after a number of high-profile setbacks, Son's investing strategy in the first and second SoftBank Vision Funds established in 2017 and 2019, has been described as one reliant on the greater fool theory. A controversial figure, Son has been called a gambler, mocked by some specialized media and dubbed the worst investor ever. , Son ranks 67th on the Forbes list of The World's Billionaires 2022, despite having had for many years the distinction of being the person who had lost the most money in history (more than $59bn during the dot com crash of 2000 alone, when his SoftBank shares plummeted), a feat surpassed by other billionaires in the following decades due to the volatile nature of the stock market, the shortcomings of financial risk and unavoidable changes in asset valuation. Son was named the world's 45th most powerful person by Forbes Magazine's List of The World's Most Powerful People. Early life and education Masayoshi Son was born as the second of four sons in Tosu (鳥栖市, Tosu-shi), a city in the eastern part of Saga Prefecture on the island of Kyushu, Japan. Son is a 3rd generation Zainichi Korean. Zainichi Koreans are ethnic Koreans with permanent residency or citizenship in Japan. Son's grandfather, Son Jong-kyung, moved from Daegu to Japan during the Japanese colonial period, where he worked as a miner. His father is Son Sam-heon. His father and other Koreans illegally built their houses on land that was owned by Japan National Railways, which caused them trouble with the authorities. His father raised pigs and chickens on that land, and started an illegal sake business that eventually