A common equity tier-1 instrument (CET-1 instrument) is an instrument (capital instrument) that belongs to a bank’s common equity tier 1 capital (CET-1). It is any share, note or other security that constitutes tier 1 capital (T-1 capital).

The main examples of common equity tier-1 instruments include:

• Common shares (portions of ownership in the bank, with the highest level of loss absorption capacity).
• Perpetual non-cumulative preference shares (these shares pay a fixed dividend but do not accumulate unpaid dividends if not distributed).
• Contingent convertible bonds (CoCos) (bonds that automatically convert into equity or are written off when certain trigger events occur, such as a drop in the bank’s capital ratio).
• Common equity tier-1 instruments may also include those related to retained earnings (profits that are reinvested into the bank, contributing to its capital base).