Grocers are finding supplies of popular products going from plentiful to almost zero from week-to-week as demand grows, with COVID-19 remaining a factor across the U.S. and reports of stock-outs growing more common. “The fact is, it’s like whack-a-mole,” Vivek Sankaran, CEO of Albertsons Cos., said on a conference call recently. “On any given day, something is out of stock in the store.”