Online drug markets operating on the 'darknet' ('cryptomarkets') facilitate the trade of illicit substances at an international level. The present study assessed the longitudinal impact on cryptomarket trading of two major disruptions: a large international law enforcement operation, 'Operation Onymous'; and the closure of the largest cryptomarket, Evolution.

Almost 1150 weekly snapshots of a total of 39 cryptomarkets were collected between October 2013 and November 2015. Data were collapsed by month and the number of unique vendor aliases operating across markets was assessed using interrupted time series regression.

Following both Operation Onymous and the closure of Evolution, significant drops of 627 (p=0.014) and 910 vendors (p<0.001) were observed, respectively. However, neither disruption significantly affected the rate at which vendor numbers increased overall.

Operation Onymous and the closure of Evolution were associated with considerable, though temporary, reductions in the number of vendors operating across cryptomarkets. Vendor numbers, however, recovered at a constant rate. While these disruptions likely impacted cryptomarket trading at the time, these markets appear resilient to disruption long-term.