Brazil's largest bank failure in recent history, Banco Master, has led to an aggressive crackdown on public pension funds, which were among its creditors. Several state and municipal pension funds were heavily exposed to the mid-sized lender's securities, raising questions about their investment strategies. The National Monetary Council approved a new regulatory framework that took effect in February. The changes have raised concerns about financial stability and financial impact on pension funds when interest rates fall, potentially setting them up for shortfalls in the future. The new rules restrict only 176 of Brazil's 2,133 public pension fundees from investing outside federal government debt.