U.S. stock losses accelerated throughout the morning after a reading on manufacturing activity in the U.S. fell into contraction in August. A strong U.S. dollar and weak global demand have impeded manufacturing growth for months. Costco (COST) - Get Report fell after reporting a flat reading on comparable-store sales for August and the recent quarter. The warehouse chain is just the latest retailer to suffer from less foot traffic and increased e-commerce spending. Infoblox (BLOX) climbed after narrowly beating profit and sales estimates over its recent quarter. The cybersecurity firm rallied a day earlier on reports it has begun the process of selling itself after activist pressure. Walgreens (WBA) - Get Report was added to Credit Suisse's Focus list. Analysts said its Rite Aid (RAD) - Get Report acquisition should boost cash flow and drive its stock price higher.