Costco stock rises on Mizuho upgrade as December sales report nears
New York, January 6, 2026, 18:45 EST — After-hours Costco Wholesale Corp shares rose on Tuesday, extending a bounce after a broker upgrade as investors looked ahead to a closely watched monthly sales update. The warehouse retailer is due to release December sales results on Wednesday. The report is a quick read on comparable sales — sales at stores open at least a year — and can shift expectations for margins and membership momentum early in the new year. investor.costco.com Costco shares closed at $888.96, up about 1.5%, and were little changed after hours at $889.10. Yahoo Finance Mizuho upgraded