Over the years, Berkshire has rolled up leading positions in a myriad of sectors across its 63 operating subsidiaries.
In 2009, in its biggest deal yet, it acquired the rest of Burlington Northern Santa Fe railroad it didn't already own, the second-largest freight line in the U.S. It also took on Geico, now the second-largest auto insurer. It also owns nearly one-third of packaged food giant Kraft Heinz.
Buffett has also ridden to the rescue more than once, injecting money into Goldman Sachs, Bank of America and General Electric to help them navigate the financial crisis. The billionaire also took on an active role in managing Salomon Brothers in the late 1980s, after a scandal involving rigged Treasury bond auctions.
The company's $170 billion portfolio of stock holdings doubles down on Buffett's America-focused bet, specifically on consumers, whose spending makes up more than two-thirds of the U.S. economy.
Berkshire holds large stakes of lenders (like M&T Bank), household product makers (such as Gillette), food and beverage companies, communications and travel providers and the quintessential American gadget maker, Apple. Its five biggest holdings are Wells Fargo and Bank of America, Apple, Coca-Cola and American Express.
Over his career, Buffett developed his buy-and-hold investment style inspired by Benjamin Graham. Berkshire's longest-held stock investment is American Express, which it began buying in the 1960s, building up to a 17 percent stake currently.
More recently Buffett has changed his mind about airlines, taking on sizable stakes in four of the nation's largest carriers, while exiting stakes in former American industrial stalwarts General Electric and IBM.
And though he admits he regrets missing out on Amazon and Google parent Alphabet, his recent embrace of Apple shows Buffett is closely watching for the next big opportunity.
"This game of economic miracles is in its early innings," Buffett wrote in an essay that appeared in Time magazine earlier this year. "Americans will benefit from far more and better 'stuff' in the future."