Warren Buffett's Berkshire Hathaway reduced its stake in Apple again, selling an estimated 116 million shares. This is the second quarter in a row that Buffett has trimmed his holdings in the tech giant. While Apple remains Berkshire's largest investment, Buffett may have sold due to valuation concerns, as Apple's stock has rallied significantly in recent months. Despite the sale, Berkshire is still Apple's largest shareholder outside of index funds.