The 21-month-long rally of U.S. stock markets has shown no signs of weakening. September is historically the worst-performing month on Wall Street. But is year, with just five trading days left, major indexes are trading in the green month to date. Intermittent volatility, however, may appear due to weak economic data, earnings results below expectation or unforeseen geopolitical conflicts. In this regard, the inclusion of some defensive stocks from the food industry will safeguard your portfolio if the mar ...