Central bank balance sheets: assets, liabilities, equity

Book equity is capital and reserves plus loss-absorbing buffers: BOJ provisions and the Eurosystem's revaluation accounts, which are mostly unrealized gold gains. Mark-to-market equity also includes unrealized gains and losses on securities and the Fed's deferred asset.

• BOJ: assets are 95% of GDP and it holds ~37% of Japan's government debt. Book equity is thin (2.2% of assets). But ¥57.1tn of unrealized ETF gains more than cover ¥45.4tn of unrealized JGB losses (FY2025, to 31 Mar 2026), so mark-to-market equity rises to ~¥26tn (3.9%).
• Fed: $47.7bn of capital against a $233bn deferred asset and $844bn of unrealized losses (end-2025), which puts mark-to-market equity near −15% of assets.
• Eurosystem: the €1.2tn revaluation accounts (gold) give a large cushion. Unrealized losses on bonds held at amortized cost aren't in the weekly statement and are left at zero. Enter a figure to test it.

Consolidating the BOJ with the government doesn't make the debt disappear. It turns long-dated JGBs into bank reserves that pay the policy rate (¥460tn of current deposits).