W ichai Thongtang is a powerful and low-profile Thai billionaire who made his fortune through a combination of his career as a corporate lawyer and his exceptionally shrewd investments. He rose to prominence as the lawyer for some of Thailand's most powerful business and political figures, including the former prime minister Thaksin Shinawatra. This work gave him deep insights and connections into the country's corporate world, which he leveraged to build his own massive investment portfolio.

He is known for being a savvy value investor, taking significant stakes in companies that he believes are undervalued. His most valuable and successful investment is his large stake in Bangkok Dusit Medical Services, one of Thailand's largest and most prestigious private hospital operators. He also has major holdings in the cable television operator, CTH, and various other businesses. His ability to identify and invest in successful companies has made him one of the wealthiest individuals in Thailand.