Costco Wholesale noted earlier today that total sales in August rose 6% on a year-over-year basis to $4.84 billion, while same-store sales edged up 2.0%. Excluding the impact of acquisitions and other items, August's same-store sales would have risen 1.0% domestically and 8.0% overseas.

For the fiscal year's fourth quarter, Costco's net sales rose 3% to $20.06 billion and same-store sales rose 5%. Through company's full fiscal year (which ended on) September 2, total sales were 7% higher at $63.06 billion, with same-store sales up 6%.

In late trading, COST is sitting with a 4% loss. Some of this could be attributed to broader-market weakness, but it's also likely that expectations were a little inflated heading into the retailer's sales report. Heading into today, Schaeffer's Volatility Index for COST stood at a new annual low of 0.05, indicating an extreme amount of complacency from the options-trading crowd. Short interest is also low on the shares, while analysts are split between buys (5) and holds (8).

Technically speaking, Costco shares have been slowly fighting higher along long-term support at their 10-month and 20-month moving averages. In fact, the stock has endured just 2 monthly closes beneath this trendline due dating back to September 2003. Today's decline is a modest setback, prompting the shares to gap beneath their 10-day and 20-day moving averages, but its long-term uptrend still appears to be solid.