U.S. stocks opened sharply lower Tuesday as fears about Chinese growth slams global markets. Chinese manufacturing numbers showed the economy is clearly slowing down and the ripples effects are causing global markets to tumble. There are some upgrades, however. Deutsche Bank has upgraded airlines American (AAL) and Delta (DAL) on valuation. Dollar Tree (DLTR) says it had a net loss in the quarter but its merger with Family Dollar is starting to show some traction and increase sales. Penn West Petroleum (PWE) will cut its head count by 35%, suspend its dividend, and slash capital spending as it deals with volatile oil prices. Hollywood is on track for one of its best summers ever at the box office. A big part of that has been bringing in young adults to the theater. Ticket prices are expected to hit $4.4 billion in the United States and Canada, a 8% increase over last year. Yahoo (YHOO) CEO Marissa Mayer is expecting identical twin girls in December. She made the announcement on her tumblr blog.