That hasn't just benefitted Buffett, but also Apple shareholders in general. The company's stake in Apple Inc. climbed in value to $48.5 billion as the tech giant's shares jumped 20 percent in the quarter.
And at last year's Berkshire annual meeting, Buffett said that he has long admired Amazon CEO Jeff Bezos, but he blew the chance to invest in it early on when the stock was priced more reasonable.
The Berkshire Hathaway chairman and chief executive officer said "one of the fellows in the office that manage money" made the purchases, a reference to investment managers Todd Combs and Ted Weschler.
Buffet further added, "Yeah, I've been a fan, and I've been an idiot for not buying" [Amazon shares.] "But I want you to know it's no personality changes taking place".
Before then, the company's stock bets were dominated by banks and other financial services and consumer goods groups such as Coca-Cola.
Warren Buffett bought a majority of the Borsheim's stock in the '80s and it paid off.
Buffett has mostly avoided technology-related stocks over the years, saying he didn't understand the products and markets well enough.
The patience afforded to Bezos is starting to pay off. Amazon reported a record US$3.6b profit in the first quarter, although its pace of sales growth had slowed. In 2016, Berkshire has a last major acquisition.
Berkshire Hathaway also has significant stakes in companies like the food conglomerate Kraft-Heinz.
The company this week signed a deal to pump US$10b into Occidental Petroleum to fund the oil and gas company's US$55b takeover of rival Anadarko.
Mega-investor Warren Buffett says that Apple's most recent earnings confirm "the reason [my firms owns] $50 billion-plus of Apple". He explains, "Mr. Buffett has commented pretty negatively on the airline space over the years, and actually speaks a lot about his poor experience with his U.S. Airways investment".