Howard Marks didn’t set out to become one of the most widely read thinkers in finance. When the Oaktree Capital co-founder wrote his first investment memo in 1990, he mailed it to a few dozen clients, and he heard nothing back for 10 years. That changed in January 2000 when he put out his memo titled “Bubble.com,” with his warning that investors’ blind faith in the internet was setting up a fall. “This was the first of my memos to engender any response from readers,” Marks said. “It describes the psychology of market bubbles in the context of a dot-com boom that would shortly become a dot-com bust when equity valuations fueled by excessive belief in the ‘the new, new thing’ fell back to earth.” Within months, the dot-com boom had collapsed, turning Marks into one of Wall Street’s most respected voices. Since then, Marks has written more than 160 memos exploring market psychology, risk and investor behavior. This week marks his 35th anniversary of his investment memos. To celebrate the milestone, Oaktree is releasing a digital archive of all Marks’ writings along with a collection of his 45 favorites. Buffett’s endorsement One of Marks’s early admirers was Warren Buffett. The Berkshire Hathaway CEO first crossed paths with Marks and his longtime partner Bruce Karsh when they both owned debt in the same distressed company. Buffett handed them his proxy during the restructuring, leading to a successful outcome and an enduring friendship. After Marks mentioned Buffett in one of his memos, he sent him a copy. Buffett replied with a note offering to endorse Marks’s future book. “He said, ‘If you ever write a book, I’ll give you a blurb for the jacket,'” Marks recalled. That became the catalyst for “The Most Important Thing,” which was Marks’ first book. Buffett delivered on the promise, writing that “when I see memos from Howard Marks in my mail, they’re the first thing I open and read. I always learn something.” No AI bubble yet Marks’ approach centers on reading the psychology of markets rather than forecasting them. That philosophy helped him identify the dot-com bubble, warn about excessive risk-taking in 2007, and call a bottom during the depths of the 2008 financial crisis. Today, he sees echoes of those cycles, but he stops short of calling the current AI-driven market a bubble. “Valuations are high but not crazy,” Marks said in an interview with CNBC’s Sarah Eisen . “Expensive and going down tomorrow are not synonymous.” At 79, Marks shows no sign of slowing down. He said the memos are a way to remind readers and himself that markets are as much about behavior as they are about numbers. “Writing the memos is an absolute joy for me,” he said in a statement. “They serve as the vehicle through which I share my thinking with the investment community, allow me to connect with Oaktree’s clients and employees, and serve as my creative outlet. I plan to keep at it.”