The article discusses how covered bonds became a popular financial tool in Europe, thanks to lobbying by German mortgage banks. These bonds help stabilize the financial system by providing banks with stable funding and investors with safe options. They also reduce the need for risky mortgage securitization. However, they can also lead to more household debt by making it easier to get mortgages. Overall, covered bonds are seen as a simpler and safer way to finance homes compared to other riskier options.