The world and nation's biggest chain, Leawood, Kan.-based AMC Theatres, last week said that it did not plan to open its 1,000 theaters until Hollywood studios start releasing big movies again. That, exhibitors hope, will start with Christopher Nolan's "Tenet" on July 17, followed by Disney's "Mulan" on July 24. AMC recently raised $500 million in new debt to help it withstand the closures.