Berkshire Hathaway slashed its big stake in Apple by nearly 50% in the second quarter to about 400 million shares from 789 million shares in the first quarter, according to information in the company’s 10-Q report released Saturday. Berkshire now holds about 2.6% of Apple and the stake was worth about $88 billion based on Friday’s closing price of $219.86. The reduction in the Apple stake wasn’t a surprise but the size of the cut was unexpected.