Largest European banks in 2019, by cost/income ratio

The cost to income ratio (C/I ratio) is an important financial metric in determining the profitability of banks. The measure looks at the cost of running operations as to a bank’s operating income. Lower ratios mean that a bank is running more profitably whereas a higher C/I ratio indicates that the bank's operating expenses are too high. In Europe, cost to income ratios vary from over 80 percent in Germany to just over 40 percent in Norway.

Profitability and stability

Low profitability has been highlighted several times by the ECB as a key risk to the financial stability of the Euro area. Prolonged low profitability can have a knock-on effect to an economy’s growth. On the other hand, sustained periods of higher than average profitability can also mean trouble as was seen in the period running up to the financial crisis.

Indicators of size

Rankings of banks can be constructed using a multitude of indicators. Frequently employed to determine the size of a bank, is market capitalization, or the total dollar market value of a company's or bank's outstanding shares. Market capitalization is calculated from the current market price of one share and the number of shares outstanding for a company. Another indicator of a banks size is its total assets.