This paper examines firm heterogeneity in terms of size, wages, capital intensity, and productivity between domestic and foreign-owned firms that engage in intra-firm trade, firms that export and import, firms that import only, and firms that export only. As previously documented, heterogeneity between different groups of trading firms is substantial. Taking into account intra-firm trade in addition to exporting and importing yields new insights into the productivity advantage previously established for exporting firms. The results presented here show that this premium accrues only to exporters that also import and to exporters that also engage in intra-firm trade, but not to firms that export only. Using simultaneous quantile regressions, the paper illustrates that heterogeneity within different groups of trading firm is equally large. Some of this within-group heterogeneity can be attributed to differences in trading partners. JEL classification: F14, F23, F24