Walmart is suffering rising thefts at stores that could cause price hikes and store closures if the issue continues, Walmart CEO Doug McMillon told CNBC’s “Squawk Box” Tuesday. “Theft is an issue. It’s higher than what it has historically been,” McMillon said. Target, another big-box retailer, also faces the same problem. Last month, Target Chief Financial Officer Michael Fiddelke said shoplifting has increased about 50% year over year, causing more than $400 million in losses during this fiscal year alone.