This article considers how the monetization of the street art world is affecting the ecosystem of expressions found in the street. It takes as a point of departure that a central quality of street art is its potential to turn public space into a site of exploration. What is meant by this, briefly, is that the presence of ephemeral street art can motivate people to explore their surroundings and perhaps question how public space is being used and how they want it to be used. This article argues that the ongoing monetization of the street art world may lead to the fossilization of urban public space – a situation where the otherwise constant flux of visual expressions in the street may come to a halt as the growing presence of sanctioned work...