This isn’t just true of fashion retailers like American Eagle Outfitters, which is down more than 28 percent this year, or Talbots, off 41 percent. Even Starbucks, whose coffeehouses have become a ubiquitous feature of the American landscape, just reported a decline in same-store sales for the first time. I confess to being a Starbucks regular — I waited in line for my venti half-caf before sitting down to write this column — but its shares are near 2 1/2-year lows.  Part of that drop is because the United States economy seems to be slowing, and the meltdown in the housing sector is affecting consumers’ willingness to spend.  But Wall Street veterans like Byron Wien, who spent decades at Morgan Stanley and is now chief investment strategist at Pequot Capital, also question whether the Peter Lynch approach makes sense anymore. “Times change; markets evolve,” he notes. “What might have worked in the 1970s and 1980s may not work today.”  In part, Mr. Wien says that’s because there is faster growth outside of the United States today in countries like India and China, “and you’re not likely to hang out in those places, even if you visit them.”  What’s more, he says, the sectors that have boomed in recent years have included commodities and energy, “and they’re not the kind of thing that are likely to be part of your everyday experience.”  “Home Depot is a terrific place to shop,” he adds. “But it’s been a disappointing stock. Understanding balance sheets and being able to make earnings projections is more important than anecdotal experience.”  Now semiretired, although he still works with younger Fidelity analysts, Mr. Lynch says he never claimed that investing was simple — or easy: “People take this to the extreme and say, ‘Lynch says you can go to the mall and make a ton of money.’ ”  “You got to do the research,” he adds. “These are not lottery tickets. You’ve got to ask what inning of the ballgame are we in? Is this company financially solid? Are they profitable? When you’re in every mall in the U.S., and there’s nowhere to go, it’s hard to grow.”  Kimberly Greenberger, who covers specialty apparel retailers like American Eagle, J. Crew and Abercrombie & Fitch for Citigroup, wouldn’t knock Mr. Lynch. But she, too, cautions that a packed store on the Friday after Thanksgiving, or even the entire month of December, is very different from a potential winner on Wall Street.  “They’re going to be very busy,” she says. “But these retailers will be judged on year-over-year revenue growth and it’s very difficult for individuals to judge sales relative to last year.”  IN fact, she adds that while there are names in her sector that she likes, like Gap and TJX, owner of T.J. Maxx and Marshalls, she doesn’t consider her group suitable for buy-and-hold investors.  “These are volatile businesses,” she says. “Their problem is figuring out today what I’m going to respond to emotionally next spring, and that’s just a very, very difficult bar to hit on a regular basis.”  A version of this article appears in print on , on Page 32 of the New York edition with the headline: The Store Is Jumpin’. The Stock Isn’t. Order Reprints| Today's Paper|Subscribe
One classic bit of investor folklore — the retailer you discover at the mall whose stock ends up going through the roof — may no longer be helpful.