In the fall of 2008, global markets were failing. Lehman Brothers, an investment bank with $600 billion in assets, filed for bankruptcy protection on Sept. 15 of that year, an inflection point in the economic slowdown that brought unemployment rates as high as 10 percent.
Two weeks later, during a single day on Sept. 29, the U.S. stock market lost $1.2 trillion in value as the Dow dropped 778 points, nearly 7 percent.
"You just felt like the world was unraveling," a senior equity trader named Ryan Larson told The New York Times that day. "People started to sell and they sold hard. It didn't matter what you had — you sold."
But there was one big investor who had a different outlook: Berkshire Hathaway CEO Warren Buffett.
In fact, Buffett was buying.
"I've been buying American stocks," Buffett wrote in a an opinion piece for The New York Times on Oct. 16, 2008. Berkshire Hathaway also made big investments during the crisis, backing General Electric and Goldman Sachs.
Buffett understood the severity of the crisis; he told CNBC that year it was like an "economic Pearl Harbor." So why was he buying stocks that were rapidly falling in price when everyone else was socking cash under their pillow?
"A simple rule dictates my buying: Be fearful when others are greedy, and be greedy when others are fearful," Buffett wrote in the Times.