The rapid growth of aquaculture in Bangladesh over the past 30 years has been facilitated by the proliferation of fish traders and retailers, but comparatively little is known about the organization and behavior of actors in these segments of the aquaculture value chain in Bangladesh. We conducted a comprehensive statistically representative study with 329 aquatic product traders in 31 markets from seven districts in south and southwest Bangladesh between January and May 2021 to address this knowledge gap. Five distinct categories of trader were identified: (1) wholesalers, who buy fish from farmers and traders for sale to other traders and retailers (N =50); (2) auctioneers (known as arotder in Bangla language) who earn commission from buyers and sellers (N =75); (3) depots, who receive shrimp and freshwater prawn from farmers and assemblers, for sale to processing factories (N=62); (4) assemblers, who mainly buy small quantities of crustaceans from farmers and transport them to market (N=42); (5) retailers, who purchase small quantities of fish from other traders for sale to consumers (N=100). The total number of traders in surveyed markets increased by more than 175% within the past 10 years. Numbers of wholesalers grew faster than any other category of traders. Wholesalers trade the largest average volumes among the five actor types (526 t/year), of which 88% is fish (Table 1). This finding is consistent with results from farm surveys conducted simultaneously in the same zone which show a big increase in fish production over this period. Trading businesses are predominantly family owned and operated, and mainly create employment opportunities for men (99%). Fish trading created an average of 14 days of employment per ton of fish across all trader types, amounting to a total 2,542 full time equivalent (FTE) jobs created by traders in our sample of which 51% family labor and 49% hired. Trader’s annual working capital requirements, operating costs and gross margins are substantial, averaging $18,630, $17,000, and $22,722, respectively across all trader types. Average marketing margins earned on each transaction average 6.0% of the sales value, ranging from 2.9% for auctioneers, to 14% for retailers. These are relatively modest margins, indicating that the rate profit extracted by traders is not excessive.