Warren Buffett's Berkshire Hathaway sold 600 million shares of Apple, missing out on over $35 billion in 2024.Buffett's company left significant gains on the table as Apple's stock rose by 31% this year.Berkshire Hathaway also incurred losses with its Occidental stake, which fell by 21% this year.Leaving such a substantial amount on the table raises concerns about Berkshire Hathaway's future investments.