In the face of decreasing returns on investments and the growing influence of sustainability requirements, foundations have had to adjust the way they invest their assets. Sustainable investments have shown themselves to be as robust in terms of their returns as conventional investments and—more than that—they can support foundations’ goals much more effectively. But only very few foundations implement sustainable investment strategies. The present study analyses the reasons for this, by means of interviews with personnel responsible for assets. The interviewees operate as ‘sense givers’ who have to kickstart a process of strategic readjustment. The reference framework for their ways of thinking and acting has been investigated using framing analysis. So-called sense givers’ isolated position in their foundations is the rather disturbing finding of this study. Familiar strategies of action seem to be of little help in their endeavours. This is frequently expressed in sometimes poignant calls for external guidelines and role models, while specific ideas about courses of action remain relatively vague. This applies particularly to large foundations where strategic readjustments are hindered by complex structures and hierarchies, whereas in small-scale entities, decisions follow shorter, face-to-face pathways. The imperative of carving out a complex sustainability discourse in their foundations drives sense givers to activities like networking inside and outside their foundations in order to exchange ideas and build alliances, for example within the German Association of Charitable Foundations. Investment managers need first of all to develop new strategies to convince the range of stakeholders in their foundations.