Plus: Costco shares fall after the retailer says it will raise its membership fees in September. Pfizer shares rise as the drugmaker says it would schedule additional human testing for an experimental once-daily weight-loss pill. J.R. Whalen reports.\xa0\n\n\n\nSign up for the WSJ's free What's News newsletter.\xa0\n\nLearn more about your ad choices. Visit megaphone.fm/adchoices