There are few financial service stocks that could be considered "defensive" stocks. Hence the importance of bank stocks like $Bank of New York Mellon(BK)$ and $State(STT)$ . With these "custody" banks, very little credit risk is at play. Instead, they earn their money mostly through fees by being the "infrastructure" of the financial service world. For example, they charge fees to act as custodian of assets, provide escrow services, offer fund accounting services, securities lending services, act as trustee to bonds, provide treasury services to large companies, and general asset management. Importantly, the range of their services are counter-cyclical. Some services do well in high interest rate environments while others perform better in low interest rate environments as the markets require different services in their search for yield.