When talking about actuarial models, ruin theory plays a pivotal role in understanding the financial health and sustainability of insurance companies. Essentially, ruin theory helps us answer one pressing question: What are the chances that an insurer’s surplus—or financial reserves—will dip below zero, causing insolvency or ruin? It’s a concept rooted deeply in probability and risk management, and it’s indispensable for actuaries who want to keep companies financially sound over the long haul.