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 Boxâ€ 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.