This article assesses the contribution of intensive and extensive margins in the firm, destination and product dimensions to yearly changes in total Portuguese exports and imports of goods. In addition, we compare cohorts of international traders in terms of number of firms and trade flows. Moreover, the long time-horizon considered in the article makes it possible to observe the impact of two important events: the great trade collapse that occurred in 2008-2009 and the Portuguese economic and financial adjustment program that was initiated in 2011 and lasted until mid-2014. The analysis builds on a detailed database of international trade transactions in the Portugese economy in the period 1995-2015.