This paper introduces several market-based measures of systemic risk and examines how they can inform the vulnerability assessment of South African banks from the perspective of both markets and regulators. We make an empirical comparison of three systemic risk measures - DCoVaR, Marginal Expected Shortfall (MES), and SRISK in the context of six South African banks, which constitute 92% of the total assets in the South African banking system. We obtain the rankings of these institutions in terms of their contributions to systemic risk across the different measures. In addition, we investigate how the measures may be aggregated to estimate the projected tails of the distribution of GDP growth in order to inform macroprudential policy considerations. This analysis motivates the use of a suite of measures to monitor the level of systemic risk in the financial system, as well as, their implied risk to real economic outcomes in South Africa.