Warren Buffett made Apple (AAPL) Berkshire Hathaway's (BRKA, BRKB) largest equity position. The article notes that a hypothetical $10,000 investment in Apple 10 years ago, with dividends reinvested, would be worth approximately $122,400 today. Apple's stake once accounted for 40% of Berkshire's stock portfolio and currently stands at 20% of its roughly $360 billion portfolio.