Key TakeawaysCostco saw sales jump 9% in September compared to the same month a year ago.Net sales for the month totaled $24.6 billion.One reason for the bump, according to Costco, was “abnormal consumer activity” due to port strikes and Hurricane Helene. Shoppers didn’t pinch pennies at Costco (COST) last month. The popular wholesaler said Wednesday that it saw sales jump 9% in September compared to the same month a year ago—with net sales for the month totaling $24.6 billion. One reason for the bump in sa ...