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Common Equity Tier 1 (CET1)

Common Equity Tier 1 (CET1)

What Is Common Equity Tier 1 (CET1)?

Common Equity Tier 1 (CET1) is a part of Tier 1 capital that is for the most part common stock held by a bank or other financial institution. It is a capital measure presented in 2014 as a prudent means to shield the economy from a financial crisis, generally with regards to the European banking system.

It is expected that all Eurozone banks ought to meet the base required CET1 ratio of 15.1% of risk-weighted assets in 2022, up from 14.9% in 2021.

Grasping Common Equity Tier 1 (CET1)

Following the 2008 financial crisis, the Basel Committee planned a transformed set of international standards to survey and monitor banks' capital adequacy. These standards, by and large called Basel III, compare a bank's assets with its capital to determine in the event that the bank could stand the trial of a crisis.

Capital is required by banks to retain unexpected losses that emerge during the normal course of the bank's operations. The Basel III system fixes the capital requirements by restricting the type of capital that a bank might remember for its different capital tiers and structures. A bank's capital structure comprises of Tier 2 capital, Tier 1 capital, and common equity Tier 1 capital.

Computing Tier 1 Capital

Tier 1 capital is calculated as CET1 capital plus extra Tier 1 capital (AT1). Common equity Tier 1 involves a bank's core capital and incorporates common shares, stock surpluses coming about because of the issue of common shares, retained earnings, common shares issued by auxiliaries and held by outsiders, and accumulated other complete income (AOCI).

Extra Tier 1 capital is defined as instruments that are not common equity but rather are eligible for inclusion in this tier. An illustration of AT1 capital is a contingent convertible or hybrid security, which has a perpetual term and can be changed over into equity when a trigger event happens. An event that makes a security be changed over completely to equity happens when CET1 capital falls below a certain threshold.

CET1 is a measure of bank solvency that checks a bank's capital strength.

This measure is better caught by the CET1 ratio, which measures a bank's capital against its assets. Since not all assets have similar risk, the assets acquired by a bank are weighted in view of the credit risk and market risk that every asset presents.

For instance, a government bond might be portrayed as a "no-risk asset" and given a zero percent risk weighting. Then again, a subprime mortgage might be classified as a high-risk asset and weighted 65%. As per Basel III capital and liquidity rules, all banks must have a base CET1 to risk-weighted assets (RWA) ratio of 4.5%.

Common equity Tier 1 ratio = common equity tier 1 capital/risk-weighted assets

A bank's capital structure comprises of Lower Tier 2, Upper Tier 1, AT1, and CET1. CET1 is at the lower part of the capital structure, and that means that any losses incurred are first deducted from this tier in the event of a crisis. Assuming that the deduction brings about the CET1 ratio dipping under its regulatory least, the bank must build its capital ratio back to the required level or risk being overwhelmed or closed down by regulators.

During the rebuilding phase, regulators might prevent the bank from paying dividends or employee bonuses. On account of insolvency, the equity holders bear the losses originally followed by the hybrid and convertible bondholders and afterward Tier 2 capital.

Stress Tests

The European Banking Authority conducts stress tests utilizing the CET1 ratio every once in a while to comprehend how much capital banks would have left in the adverse event of a financial crisis. The consequences of these tests have shown that most banks would have the option to endure a crisis.


  • Common equity Tier 1 covers liquid bank holdings like cash, stock, and so on.
  • Many bank stress tests against banks use Tier 1 capital as a starting measure to test the bank's liquidity and ability to endure a difficult monetary event.
  • Extra Tier 1 capital is made out of instruments that are not common equity.
  • The CET1 ratio compares a bank's capital against its assets.
  • In the event of a crisis, equity is taken first from Tier 1.


What Is the Minimum Tier 1 Capital a Bank Can Have?

The Basel Accords illuminated the base capital requirements for banks. They must keep a base capital ratio of 8%, of which 6% must be Tier 1 capital.

What Does a Low CET1 Ratio Mean?

A low CET1 ratio infers a deficient level of Tier 1 capital. In such a case, a bank will most likely be unable to retain a financial shock and may should be rescued rapidly in the event of a financial crisis.

How Are Tier 1 Capital and CET1 Capital Different?

CET1 capital is one part of total Tier 1 capital. The other is known as extra Tier 1 capital (AT1). AT1 + CET1 = Tier 1 capital.