As power systems transition toward high shares of inverter based renewable generation, the way we define, assess, and ensure system stability must evolve. Traditional sources of inertia, synchronizing power, and voltage support are becoming less prevalent, while increasing power transfers and grid reinforcements push operation closer to technical stability limits. This presentation outlines the emerging challenges for system stability in renewables-based grids, including frequency, voltage, and rotor angle stability, and highlights the growing importance of stability constrained transfer limits. It discusses how regulatory frameworks can better integrate stability related assessments into operational planning and real time processes.