NEW YORK (AP) â¿¿ Shares of Wal-Mart slipped 2 percent in early trading Monday and J.P. Morgan downgraded its stock, voicing concern that growing economic pressures will weigh on its momentum. THE SPARK: Analyst Christopher Horvers lowered his rating to "Neutral" from "Outperform" and expects Wal-Mart's stock will trade at $75 in the next 12 months, down from his estimated target price of $84. Horvers believes sales at the world's largest retailer have peaked after three years of strong growth. The company, based in Bentonville, Ark., fixed mistakes in merchandising and pricing, but he thinks that the "low hanging fruit" is now in the company's past. Wal-Mart's business will be strained by a hike in payroll taxes, which will squeeze lower-income consumers, Horvers said. THE BIG PICTURE: Wal-Mart benefited during the recession as wealthier shoppers traded down to low-priced stores and existing customers stayed even closer to home. But soon after the recession ended in June 2009, Wal-Mart grappled with a sales slump that lasted a little more than two years, in part because of the mistakes in pricing and merchandising. In the third quarter of 2011, Wal-Mart had begun to turn that situation around after restocking 10,000 products and focusing more strongly on prices. It slashed expenses and passed some of the savings on to hard-pressed customers. The company has now notched five consecutive quarters of revenue growth at comparable stores in the U.S., a clear-cut departure from the nine straight quarters in which revenue at those stores declined. When the company posts fourth-quarter earnings on Feb. 21, most expect even more positive results from aggressive discounting and an expanded layaway programs. For lower-income shoppers, however, a slow economic recovery has affected day-to-day budget decisions more than it has for those with more disposable income. The company has seen some of its momentum slow.