See also: Milken on Drexel’s legacy and negotiating with Carl Icahn

“Kenny learned maniacal work habits from Milken,” said Don Engel, an early boss of Moelis’s at Drexel Burnham Lambert who now serves on the board of Blink Charging Co., which operates electric-vehicle charging stations. “There was no such thing as a Saturday or Sunday at Drexel.”

Car Wreck
The banker is known for deep ties to clients that stretch back decades, often forged in high-stakes M&A.

In 2003, when Moelis’s wife Julie suffered a broken back in a car wreck during a family vacation in Australia, news of the accident rippled across a worldwide web of billionaires. The Los Angeles banker was flooded with offers of medical assistance and transportation, including from Milken, his former colleague, and Rupert Murdoch.

Moelis’s entree into Wall Street was inauspicious. Morgan Stanley rejected him after he graduated from the University of Pennsylvania’s Wharton School in 1981. He joined Drexel, then regarded as a second-rate outfit. There Moelis became well-versed in exotic financial structures.

"Over a period of four to six years he got his PhD in capital structure," Milken said in an interview.

Guilty Plea
Milken pushed the young banker to work with moguls, such as media boss John Kluge, while Moelis sought out other scrappy entrepreneurs such as real estate tycoon Sam Zell. These connections endured even as Drexel collapsed and Milken went to prison, after pleading guilty in 1990 to six felony securities law violations.

Moelis landed at Donaldson, Lufkin & Jenrette, bringing along clients like Wynn. He later moved to UBS AG, where he helped the Swiss bank almost triple its share of U.S. mergers and acquisitions.

After struggling with the UBS bureaucracy and cautiousness, Moelis struck out on his own in 2007, gambling that the unfolding financial crisis presented opportunities.

"At UBS he built a powerhouse operation and ultimately decided that the only sure-fire way to cut through the red tape once and for all was to hang out his own shingle," said investment banker Lloyd Greif, CEO of Greif & Co.