Building upon the theory of a classical buyer-seller relation, we analyze empirically the spatial relation between coworking spaces and start-ups in an entrepreneurial ecosystemby addressing product market competition among coworking spaces and start-ups' life cycle stages as drivers of the level of trust among those partners. In our hand-collected sample of coworking spaces in Germany's seven biggest cities, our findings indicate the higher product market competition among coworking spaces in a region is, the more mature start-ups (identified by receiving ex- ternal financing) are likely located in this region. Nascent start-ups are found to be related to product market competition among coworking spaces in a hump-shaped pattern indicating that they are more likely tenants of coworking spaces if market competition of coworking spaces is neither too low nor too high. A European study with WeWork data supports our findings and a difference-in-differences approach mitigates endogeneity concerns.