The thesis of the above-named article in June 2012 2p2 Mag is that Wal-Mart (WMT) stock is so undervalued compared to its EPS and P/E ratio that it "has to" go up.
One time I bit for a similar deal on a stock that "had to" go up, it was MSFT circa 2004. They had mondo earnings and a relatively low PE (for a tech co.) and the stock had gone nowhere in ages. Surely the market would rediscover MSFT and it would rebound to its rightful value. Bought call options. They expired worthless. Of course, AAPL was $40 then....
What I think happened with MSFT could be the same thing that's happening with WMT. Both companies have a few individuals who hold massive numbers of shares. It was rumored, for example, that Paul Allen didn't want Bill Gates to profit from a price rise in MSFT, so he would sell into the market to keep the price steady. I have no idea whether this is true, but it could be true of WMT. Maybe one of the Walton princelings hates another princeling sufficiently to manipulate the stock price.