Wal-Mart (NYSE: WMT) averages about 140 million shoppers each week in its U.S. stores and is considered a barometer of the health of consumers and the economy. Unfortunately, according to CEO Mike Duke, that health is still declining. "We're seeing core consumers under a lot of pressure," Duke said at an event in New York. "There's no doubt that rising fuel prices are having an impact." Lately, they're "running out of money" at a faster clip.

Wal-Mart has noticed a pattern during the recession where its core customers will typically shop in bulk at the beginning of the month when their paychecks come in. Due to rising gasoline prices, these customers are running out of money much faster than a year ago, and the retail giant is worried. The company is now returning to its former strategy of low prices and being a "one-stop shop" as a way to combat higher fuel prices.

Wal-Mart's fears, along with Amazon's (Nasdaq: AMZN) recent earnings miss, highlight the fact that the American consumer is still strained. Investors may want to consider avoiding funds like the Retail HOLDRs (NYSE: RTH) and Consumer Discretionary Select Sector SPDR (NYSE: XLY) for now as a correction could be coming.

Benzinga