“Stocks are losing their last line of defense. Amid a selloff that erased more than two years of gains — about $14 trillion — from global stocks now on the brink of a bear market, at least earnings stood as a potential bright spot. Those hopes are fading: analyst profit downgrades outnumbered upgrades by the most since 2009 last week, according to monthly data from a Citigroup Inc. index that tracks such changes.”