The deal whisperer: Inside the rise of Raine Group's Jeff Sine

• Jeff Sine has built a career as an unorthodox banker.
• He's advised business moguls like Masayoshi Son and Rupert Murdoch.
• The Raine Group, a media- and entertainment-focused merchant bank, is now a billion-dollar business.

From humble beginnings, Jeff Sine built a career as an unorthodox banker who offered unvarnished advice and tamed unruly transactions for business moguls like Masayoshi Son and Rupert Murdoch. He defied the odds and built merchant bank The Raine Group into an investing empire in its own right.

Insider spoke with 10 people who have worked with Sine throughout his career, including senior bankers and clients. They explained how Sine became one of the world's most influential dealmakers, the origins of his relationships with Masa and other key clients, and how he built a billion-dollar business.