Central Bank Balance Sheets and Liquidity Cycles

Central bank balance sheet expansion and contraction is the primary driver of global liquidity cycles. Understanding how QE and QT affect asset prices and currency direction is essential macro knowledge.

When central banks conduct quantitative easing (QE), they purchase assets — government bonds, mortgage-backed securities — by creating new reserves. This expands the money supply, lowers long-term interest rates, and injects liquidity into financial markets. The result is typically asset price appreciation across equities, credit, and risk assets, combined with currency weakness for the country conducting QE.

QT and its effects

Quantitative tightening (QT) is the reverse — allowing bonds on the central bank's balance sheet to mature without reinvestment, or actively selling them. This withdraws liquidity from the financial system, puts upward pressure on long-term rates, and is generally currency-supportive. The Fed's QT programme, which began in 2022, has been one of the structural supports for the dollar even as rate hike expectations have moderated.

The global liquidity cycle

Global liquidity — the aggregate of central bank balance sheets worldwide — is the single biggest driver of risk asset performance over medium and long time horizons. When the combined balance sheets of the Fed, ECB, BoJ, and PBOC are expanding, risk assets outperform and the dollar typically weakens. When global liquidity contracts, the reverse occurs.

Practical application for FX traders

FX traders do not need to forecast central bank policy precisely to use liquidity cycle awareness. The basic framework: when central banks globally are in easing mode (expanding balance sheets), favour risk-on currencies (AUD, NZD, EM) and be cautious of safe havens. When the global cycle turns to tightening, reverse the bias. This macro overlay does not replace technical analysis — it contextualises it.