Berkshire Hathaway's second-quarter 13F filing showed its U.S. stock portfolio rose to about $299.3 billion at the end of June from roughly $263.1 billion at the end of the first quarter. The company initiated one new position, added to seven holdings, reduced six and exited one. Alphabet was the standout buy. Berkshire increased its Class A holding by about 24.54 million shares, or 45.24%, to roughly 78.79 million shares valued at about $28.16 billion, and boosted its Class C stake by about 23.60 million shares, or 658.35%, to around 27.19 million shares valued at about $9.61 billion. Combined, the two share classes were worth about $37.76 billion at quarter-end, or 12.62% of the portfolio, making Alphabet Berkshire's third-largest holding behind Apple and American Express and ahead of Coca-Cola. Apple remained the largest position at about $65.95 billion, or roughly 22% of the portfolio, followed by American Express at about $51.28 billion, or 17.14%. Berkshire's top 10 holdings, counting Alphabet on a combined basis, were Apple, American Express, Alphabet, Coca-Cola, Bank of America, Chevron, Occidental Petroleum, Chubb, Moody's and Kraft Heinz. Outside Alphabet, Berkshire added to Delta Air Lines by about 17.51 million shares, or roughly 44%, lifting the stake to 57.32 million shares valued at about $5.37 billion. It also increased Lennar Class A by about 3.01 million shares and Lennar Class B by about 60,000 shares, raised Macy's by about 4.31 million shares, or 141.82%, and made a smaller addition to The New York Times of about 550,000 shares. The only new position was a small stake in D.R. Horton of 3,564 shares worth about $580,000. On the selling side, Bank of America was the only top-10 holding reduced during the quarter. Berkshire cut about 30.20 million shares, or 5.89%, leaving 483 million shares worth about $27.54 billion, or 9.2% of the portfolio, and extending the streak of quarterly reductions to two. Berkshire also reduced Ally Financial, Capital One, DaVita, Kroger and Nucor, and fully exited Constellation Brands after sharply cutting the position in the first quarter.