In Argentina in particular you have seen a pickup in volatility over the last couple of months, and it has to do with the fact that it has higher yields available and longer duration and makes it prone to volatility.
Overall, you have a very technical market pushing us to historical highs because once people got a feel for these higher levels, it has been an easy push to the upside and has been helped by lack of liquidity.
In general it's a healthy profit taking move for the EM market, and for the domestic markets in Latin America as the stock and currency markets are coming off.