Systemic risk describes threats that can trigger cascading failures across interconnected organizations, financial markets, or critical infrastructure. Unlike idiosyncratic risks affecting single firms, systemic risks propagate through networks of dependencies, contagion, or common exposures. The 2008 financial crisis exemplified systemic risk when mortgage-backed securities failures spread throughout global banking systems. Central banks and regulators closely monitor systemically important institutions whose failure could destabilize entire economies. Mitigating systemic risk requires coordination across organizations, industries, and regulatory bodies rather than individual firm actions alone.