Comparable store sales are a key indicator of a retailer's performance, as they reflect the revenue generated by the company's established stores over a certain period. A year-over-year decrease in these sales, especially during the critical holiday shopping season, suggests that Buckle may be facing challenges in maintaining sales growth. This could lead to investor concern and a potential decrease in stock price in the short term. The reported 5% decrease in total net sales further reinforces the likelihood of a negative impact on the stock.