This paper examines the evolution and impact of wholesalers in the U.S. market for manufactured goods, which has grown from 32% to 47.4% of all transactions between 1992 and 2012. The growth is largely driven by the expansion of "superstar" wholesalers, the top 1% of the industry, which have increased their market share and markups. The rise of these large firms is attributed to their ability to source goods globally and expand their domestic distribution networks, both of which require scale economies. Counterfactual analysis shows that while wholesalers have increased their market power and markups, they have also provided benefits to buyers, such as access to a wider variety of globally sourced products and reduced procurement costs. The paper uses large administrative datasets to estimate a model of demand and supply, allowing for the analysis of market concentration and welfare effects. The findings highlight the importance of scale economies and the interaction between international trade and domestic investments in shaping the wholesale sector.This paper examines the evolution and impact of wholesalers in the U.S. market for manufactured goods, which has grown from 32% to 47.4% of all transactions between 1992 and 2012. The growth is largely driven by the expansion of "superstar" wholesalers, the top 1% of the industry, which have increased their market share and markups. The rise of these large firms is attributed to their ability to source goods globally and expand their domestic distribution networks, both of which require scale economies. Counterfactual analysis shows that while wholesalers have increased their market power and markups, they have also provided benefits to buyers, such as access to a wider variety of globally sourced products and reduced procurement costs. The paper uses large administrative datasets to estimate a model of demand and supply, allowing for the analysis of market concentration and welfare effects. The findings highlight the importance of scale economies and the interaction between international trade and domestic investments in shaping the wholesale sector.