What are the financial stability implications of Central Bank Digital Currencies (CBDCs), and what risks should banks prepare for?

A Central Bank Digital Currency (CBDC) is a digital liability of the central bank, available directly to households and businesses (retail CBDC) or limited to financial institutions (wholesale CBDC). While wholesale CBDCs are relatively straightforward extensions of existing reserve systems, retail CBDCs introduce transformative risks to the banking system.

The Disintermediation Channel

The most significant risk is deposit substitution. If households can hold risk-free digital money directly at the central bank, they may shift funds out of commercial bank deposits. This matters enormously because:

• Deposits are the cheapest and most stable funding source for banks
• A migration from deposits to CBDC shrinks bank balance sheets
• Banks must replace lost deposits with more expensive wholesale funding (bonds, repo)
• Higher funding costs compress net interest margins and may reduce lending

Example: Impact on Fieldstone Community Bank

Fieldstone Community Bank has $8 billion in deposits, of which $5.2B are retail demand deposits yielding 0.5%. If a retail CBDC launches and 20% of demand deposits migrate ($1.04B), Fieldstone must replace this funding:

Incremental annual funding cost: ($650M x 3.75%) + ($390M x 4.30%) = $24.4M + $16.8M = $41.2M

This represents roughly a 12% reduction in pre-tax profit for a mid-size bank — a material hit.

Financial Stability Risk Channels

1. Digital Bank Runs

In a crisis, depositors can convert to CBDC instantly — no need to queue at branches or wait for wire transfers. This makes bank runs potentially faster and more destabilizing than ever before. The entire deposit base could theoretically flee in hours.

2. Monetary Policy Transmission

If the central bank pays interest on CBDC, it creates a new policy tool — but also a floor on deposit rates. Banks cannot offer below the CBDC rate, which constrains their ability to manage funding costs during easing cycles.

3. Two-Tier System Pressures

Smaller banks may be disproportionately affected because they rely more heavily on retail deposits and have less access to wholesale markets. This could accelerate consolidation in the banking sector.

Design Mitigants Being Discussed

• Holding limits: Cap individual CBDC balances at, say, EUR 3,000 to prevent large-scale deposit migration
• Tiered remuneration: Pay zero or negative interest on CBDC above a threshold to discourage hoarding
• No anonymity for large amounts: Reduce attractiveness relative to cash for illicit purposes
• Gradual rollout: Pilot programs (like the digital euro or e-CNY) test calibration before full launch

FRM exam tip: Focus on the deposit disintermediation channel as the primary financial stability concern. Know the difference between retail and wholesale CBDCs — most exam-relevant risks relate to retail. Understand that design features (holding limits, tiered remuneration) are the proposed solutions to the bank run amplification problem.

For more on fintech and current issues, explore our FRM Part II materials.