This article makes a case for the significance that borders have for new venture discovery. Since markets are social phenomena, new venture discoveries necessarily refer to the crossing of social borders. We draw on social systems theory and theories of social differentiation to understand how social borders are drawn. We demonstrate how this knowledge may be used to create and unfold a comprehensive market map that is useful for both the tracking of past and the anticipation of new venture discoveries. We use this map combined with illustrative cases to provide evidence that an entire quadrant of entrepreneurial opportunities is still uncharted in traditional maps for new venture discovery. We conclude that the future of new venture discovery is about the strategic transgression of social borders not only between traditional market segments or strata, but also between the function systems of society such as the political system, economy, science, art, religion, or the mass media system.