Foresight processes and activities are confronted with the task of making sense of the present, in particular by interpreting weak signals of change in the organizational environment. Although trends are considered to be important drivers of environmental discontinuities which may lead to strategic surprises, there is no operationalization from a strategic point of view. In this paper we are going to conceptualize trends as (socio-cultural) innovations. This leads to important implications. If the nature of innovation is taken seriously, then strategic trend diagnosis has to deal with two different aspects, invention and diffusion.