Costco's September Surprise: Sales Accelerate, Stock Jumps

Costco Wholesale (COST) has been a market laggard this year, with its stock up only 3.5% over the past year compared to the S&P 500's 15.6% gain. However, all of that gain occurred in just the past week, following the release of strong September sales data.

The company reported a 13% year-over-year increase in revenue for September, driven by an 11.4% rise in comparable sales. U.S. comparable sales, which had been slowing, accelerated to 12.5%. This is a significant improvement from previous months and suggests that Costco's business is reaccelerating.

A key factor behind this growth is inflation, which is driving more members to shop at Costco for its low prices. Additionally, rising oil prices have boosted sales at Costco's gas stations, and the company is capitalizing on this by opening more gas stations. Even excluding gas, comparable sales were up a solid 7.6%, indicating the core business remains strong.

Investors had been concerned about slowing membership growth and the company's ability to sustain growth amid inflation. The September results have alleviated some of those fears, showing that Costco's model is resilient and can thrive even in challenging economic environments.

The September sales data is crucial for Costco investors because it demonstrates that the company can still deliver strong growth despite broader economic concerns. The acceleration in comparable sales, especially in the U.S., suggests that Costco is gaining market share as consumers seek value amid inflation.

Costco's membership model provides a steady stream of recurring revenue, and the fact that inflation is driving more traffic to its stores is a positive sign. The company's ability to leverage its gas stations to attract customers is an added bonus, though the core business excluding gas is also performing well.

From a stock perspective, the recent surge may be just the beginning if Costco can maintain this momentum. The stock has underperformed the market this year, so any sustained improvement in growth could lead to a re-rating. However, investors should watch for whether this is a one-month anomaly or a sustainable trend.

The market's reaction—sending the stock up sharply—indicates that expectations were low and that any positive news is welcomed. If Costco continues to report strong monthly numbers, the stock could continue to recover.