The document discusses how emerging markets were negatively impacted by changes in US monetary policy in 2013. Specifically, it discusses how the US Federal Reserve's tapering of its quantitative easing program led to capital outflows from emerging markets as foreign investors shifted funds back to the US. This created "taper turbulence" in emerging markets, depreciating their currencies and stock markets. The document analyzes which emerging markets are most vulnerable to further changes in US monetary policy based on factors like foreign capital levels, current account balances, and economic growth trends. South Africa, Turkey, and Brazil are highlighted as being particularly vulnerable.