Banks buying sovereign debt is lesser of two evils

A fundamental tension in post-crisis financial architecture is driving debate over how much sovereign debt banks should be permitted to hold. Since 2007, public debt in advanced economies has nearly doubled as a share of GDP—from 69% to 108%—while regulatory frameworks have simultaneously constrained the banking system's capacity to intermediate this growing supply. The result is a market structure now dependent on leveraged non-bank investors to absorb government bonds, a dynamic that may pose greater systemic risks than allowing banks to expand their sovereign debt portfolios.

The Basel III leverage ratio, implemented following the global financial crisis, established balance-sheet-based capital requirements that penalize total assets independent of credit risk assessment. This framework proved particularly constraining for domestic sovereign bonds, which typically carry zero or minimal regulatory risk weighting but still consume balance sheet capacity. Bank for International Settlements analysis demonstrates the mechanical impact: public debt held by banks in advanced economies contracted from 25% of GDP in 2013 to 20% by 2018 as leverage ratios were phased in. Central banks provided temporary relief through quantitative easing programs, but withdrawal of these measures has left a substantial funding gap.

Into this void have stepped leveraged hedge funds. A recent analysis cited in the primary commentary notes that UK hedge funds have accumulated £100 billion in borrowed positions specifically to purchase gilts. This concentration of sovereign debt exposure among levered non-bank investors introduces distinct vulnerabilities: forced selling during market stress, redemption pressures, and procyclical deleveraging could amplify volatility or create liquidity dislocations in critical government bond markets.

Barclays has led industry advocacy for regulatory relief, estimating that exempting a portion of UK government bonds from leverage ratio calculations would free approximately £150 billion in bank lending capacity dedicated to gilts. The timing aligns with a broader regulatory reassessment: both the Federal Reserve and Bank of England are evaluating the pace and scope of Basel III implementation, with growth-friendly deregulation gaining traction among Western policymakers. While expanding bank sovereign debt holdings introduces risks—including increased vulnerability to fiscal deterioration and potential insolvency during periods of rising interest rates—the alternative architecture, in which leveraged hedge funds dominate supply absorption, presents arguably greater systemic hazard. The policy trade-off reflects an uncomfortable choice between two imperfect financial structures.