Contingent convertible bonds, often called CoCos, are debt instruments that convert into equity or suffer principal write-downs when a bank’s capital falls below a predefined trigger. Their design aims to increase loss absorption and reduce the need for taxpayer-funded bailouts. Evidence from policy institutions and academic researchers shows that CoCos can strengthen bank capital buffers in stress scenarios, but their ability to provide timely liquidity during episodes of sovereign stress is limited.
Mechanisms and immediate effects
Conversion converts debt into equity rather than supplying new cash, so CoCos do not directly create fresh funding at the moment of a trigger. Hyun Song Shin at the Bank for International Settlements has emphasized that instruments built to absorb losses can stabilize solvency metrics but cannot substitute for short-term cash when markets seize up. Viral V. Acharya at New York University Stern has argued that contingent capital improves creditor discipline and can reduce systemic risk by imposing private-sector losses, yet these benefits depend on credible trigger rules and investor confidence.
Sovereign stress, triggers, and correlation risks
Sovereign stress lowers asset values for banks with heavy domestic government exposure, tightening market access just when reserves are most needed. International Monetary Fund Monetary and Capital Markets Department analysis highlights the danger of correlated triggers when sovereign stress simultaneously weakens bank capital and investor appetite for bank equity. In those circumstances, conversion may occur at depressed valuations that dilute existing shareholders without restoring market functioning, and investors may refuse to buy newly issued shares, limiting the intended stabilizing effect.
Consequences and policy nuances
The efficacy of CoCos varies by jurisdiction, legal frameworks, and the strength of backstop arrangements. In countries with robust central bank liquidity facilities and clear bail-in laws, CoCos complement broader resolution toolkits. In smaller or politically fragile economies, public trust and legal uncertainty can convert a technical solution into a political flashpoint, disrupting credit to households, firms, and regional markets. Policymakers therefore view CoCos as part of a package that must include central bank liquidity support, credible resolution frameworks, and transparent disclosure to mitigate contagion rather than as a standalone cure for liquidity shortages during sovereign stress.