PepsiCo's (PEP -0.25%) shares have had more fizzle than fizz recently. The stock has fallen more than 10% from its peak over the last 12 months. Meanwhile, the S&P 500 index has soared over 30% during the same period. Don't pour Pepsi down the drain just yet, though. Here's why this beaten-down S&P 500 Dividend King is a stock you can buy and hold forever. Why PepsiCo stock has declined Throughout much of the last decade, PepsiCo's total returns outperformed the S&P 500. Why has the stock declined over the ...