Marks' investment firm, Oaktree, is considered one of the leading investors in distressed debt, essentially riskier debt.
He founded the firm in 1995, and since then the firm's assets under management have increased from $5 billion to about $101 billion. And Marks is estimated to have a personal net worth of close to $1.97 billion, according to Forbes.
He counts Warren Buffett as a friend and a fan. "When I see memos from Howard Marks in my mail, they're the first thing I open and read," Buffett once said.
And in an interview with Julie Segel at Institutional Investor, Marks explained the phone call that changed his life.
He was asked by his boss to meet up with an investor out in California named Mike Milken. Milken, whom many consider the father of high-yield bonds, explained that investing in safe assets isn't as smart as it appears, because they can only go down.
"If you buy AAA or AA bonds they only have direction. If you buy single B bonds, and they survive, all the surprise will be on the upside," he said.
"[You] could issue high yield bonds, they called them junk in those days, if the promised yield was high enough. And that makes perfect sense," he added.
It's all about price, according to Marks, not what you invest in:
There's not such thing as a good investment idea, until you've discussed price.
Investing well is not a matter of buying good things, it's about buying things well. And people have to understand the difference. And if you don't understand the difference you are in big trouble.