U.S. manufacturing trade has become dominated by ows within industries, even at the finest level of aggregation. We show that this is not because a few sectors dominate trade, but that intra-industry trade has become a feature of the majority of industries. The pattern is similar for the E.U. and even Chinese trade ows are becoming increasingly intra-industry. In contrast, Japanese trade is to a remarkable extent inter-industry. This di_erence cannot be explained by the composition of industries or trading partners.