How Central Bank Liquidity Impacts Global Markets

Central bank policy is the foundation of the global financial architecture. The four major central banks — Federal Reserve (Fed), European Central Bank (ECB), Bank of Japan (BoJ), and People's Bank of China (PBoC) — collectively determine the price and quantity of money for 70% of global GDP.

The transmission mechanism from central bank policy to asset prices operates through multiple channels. Interest rate channel: lower rates reduce discount rates, inflating equity and bond valuations. Bank credit channel: lower rates encourage bank lending, expanding money supply through credit creation. Portfolio balance channel: as central banks buy bonds, displaced investors move into higher-risk assets (equities, credit, crypto).

The Bank of Japan deserves special attention. Its zero-interest-rate policy and yield curve control (YCC) framework — which formally ended in March 2024 — had for years made the JPY the world's primary carry trade funding currency: investors borrowed in JPY (near 0%), converted to higher-yielding currencies, and invested in risk assets globally. Since 2024 the BoJ has been gradually normalising policy (ending negative rates and unwinding YCC), progressively compressing the carry differential. The size of outstanding JPY-funded carry positions is debated and not precisely measured; estimates vary widely across banks and research houses, so no single figure is cited here.

The current configuration: Fed pausing, ECB cutting, BoJ slowly normalizing, PBoC in targeted stimulus mode. The net effect is moderately expansionary for global liquidity — a mild tailwind for risk assets, but not the explosive liquidity injection that characterized 2020–2021.