OMAHA, Neb. (AP) — Warren Buffett’s company bet more on high-tech darling Apple and e-commerce giant Amazon during the second quarter. But it also invested billions in old-school oil producers Occidental Petroleum and Chevron. Berkshire Hathaway detailed all its second-quarter investments Monday. Wall Street follows Berkshire’s investments closely because of Buffett’s remarkably successful track record. Berkshire had already disclosed its biggest move in the quarter — investing more than $1.4 billion in oil producer Occidental Petroleum — but Monday’s filing revealed a number of smaller moves Berkshire made during the second quarter, including adding to its stakes in Apple, Amazon, Chevron, Ally Financial and Activision Blizzard.