Most 99-year-olds aren't placing multimillion-dollar bets on industries the world has written off. But Charlie Munger wasn't most 99-year-olds.

According to The Wall Street Journal's profile published Thursday, "The Untold Story of Charlie Munger's Final Years," the Berkshire Hathaway vice chairman made one of his boldest moves in 2023—a year that would be his last. After spending six decades steering clear of coal, Munger suddenly dove in headfirst and generated more than $50 million in paper gains before his death in late November.

The decision came from his longtime workspace: a library without air conditioning, where friends once dragged in ice and electric fans during a heatwave just to keep him comfortable. Seated in his recliner, surrounded by those iconic green Value Line binders, Munger still had the same sharp eye for undervalued opportunities that defined his legendary career.

Calling Out the Consensus

The trade started when Munger stumbled across an article proclaiming coal was "down the chute," according to the Journal. His reaction? "Horse feathers," he told his stepson, Hal Borthwick. While the industry had undeniably declined over the long term, Munger saw something the market missed: many coal producers—especially those mining metallurgical coal for steelmaking—remained highly profitable and deeply undervalued.

So in May 2023, Munger bought shares of Consol Energy. Later that year, he added Alpha Metallurgical Resources. By the time he passed away just weeks before his 100th birthday, Consol's stock had doubled and Alpha had surged as well. Friends familiar with the trades said the combined paper gains topped $50 million.

"He made a very large bet, and it turned out really well," Borthwick told The Journal.

Still Sharp, Still Loud

This wasn't some lucky hunch. Munger might not have been deeply involved in Berkshire's daily operations anymore—though he still held a $2.2 billion stake—but he was far from checked out. According to the Journal, he spoke with Warren Buffett every week or two. The conversations were memorable, mostly because both men had hearing problems.

"They would scream to each other," said Whitney Jackson, Munger's grandson's wife. "It was likely meant to be confidential, but anyone within a mile's radius could hear them."

Beyond Berkshire, Munger stayed busy. He remained an active board member at Costco, where his stake reportedly reached $100 million. He invested in smaller companies in Boston and Melbourne, Australia. And he continued backing hedge fund manager Li Lu's Himalaya Capital—Li being someone often called the "Chinese Warren Buffett."

The 80% Rule

In an interview with Business Insider published early this year, Li Lu explained that Munger's coal trades weren't just bold—they were methodical. "He could still go against the market consensus and live to see this stock double," Li said, noting the position remained in the Munger family portfolio and continued performing well. Li emphasized that Munger demanded unusually high odds—around 80% probability of success—before pulling the trigger. That discipline separated him from typical risk-takers, even in his final year.

At Berkshire Hathaway's annual meeting back in 2015, Munger famously said, "If people weren't so often wrong, we wouldn't be so rich." That philosophy never left him. Even at 99, he stayed alert to moments when the market got things wrong—and he acted on it.

The Last Lesson

Munger's late-stage coal investment wasn't about nostalgia or a lucky break. It was a sharp reminder that in a world quick to dismiss entire industries, there's still opportunity for those willing to look closer, think independently, and trust their own analysis. When everyone else saw only terminal decline in coal, Munger saw mispriced assets producing real cash flow for essential industrial uses.

At 99, Charlie Munger still had the conviction—and the clarity—to call out the crowd, buy when others fled, and walk away with gains most investors half his age would envy. He made his fortune betting against conventional wisdom when the numbers backed him up. Turns out, that edge never dulled.