Daniel Tsai comes from a wealthy Taiwanese family. His father Tsai Wan-tsai founded Fubon Financial Holdings. The business, now run by Daniel, and his brother Richard Tsai, has interests in several financial services including securities, banking and insurance. Daniel attained an LLM (Master of laws) Georgetown University and National Taiwan University.

Along with his brother, Daniel Tsai is a large investor in momo.com a business specializing in e-commerce and internet shopping, and mobile phone service provider Taiwan Mobile. His cousins T.Y. Tsai, Tsai Cheng-da and Tsai Hong-tu are also Taiwan based billionaires.