Warren Buffett’s Berkshire Hathaway boosted its Apple stake, bet big on energy stocks, and tweaked its bank holdings last quarter. Here’s a closer look at those 3 key moves. Warren Buffett''s Berkshire Hathaway revealed its US stock portfolio as of June 30 on Monday. Berkshire boosted its Apple, Chevron, and Occidental Petroleum stakes, and tweaked its bank bets. Here''s a closer look at the three key moves it made in the second quarter. Warren Buffett''s Berkshire Hathaway released a quarterly portfolio update on Monday, revealing its US stockholdings as of June 30. The famed investor''s conglomerate bolstered its biggest position, ramped up its energy wagers, and tweaked its financial bets in the period. Another bite of Apple Apple shares traded as low as $129 in June, nearly 30% below their peak of $183 at the start of this year. Buffett and his team likely saw the stock as a bargain, given they snapped up nearly 4 million more shares of the iPhone maker in the second quarter, raising their stake to 895 million shares or 5.6%. Berkshire counts Apple as its number-one holding, accounting for over 40% of the conglomerate''s $300 billion stock portfolio. The position has jumped in value from $122 billion to $155 billion in the past six weeks alone, thanks to Apple''s stock price rebounding by 27% in that period.