Ray Dalio
Ray Dalio, the billionaire founder of Bridgewater Associates, at times exhibited a short fuse with his employees, according to a new book.

She was one of Ray Dalio's favorites. And now she had collapsed into tears — not with ordinary crying but in a full-on meltdown, complete with chest heaving, gasping for breath, and animalistic sobbing.

Katina Stefanova, until that day, was known as the Ice Queen at Bridgewater Associates, the world's largest hedge fund. Thirty-something, with shoulder-length blonde hair, she wasn't afraid of conflict, particularly if it came with a fat check. 

She was Dalio's mentee and friend, and as she rose through the ranks in the firm, he took to telling others, "Katina is one of my people," which nearly made her blush with happiness. Some at Bridgewater even began to whisper that she could someday be a candidate to succeed Dalio.