The asset side: what the Fed owns
The Fed's assets are overwhelmingly securities bought in past policy operations: U.S. Treasuries across the maturity spectrum and agency mortgage-backed securities acquired during rounds of quantitative easing. Smaller lines include loans to banks through the discount window and whatever emergency facilities are active at the time. The Fed publishes the whole sheet weekly in its H.4.1 release, every Thursday afternoon — one of the most-watched routine documents in finance.
The liability side: what the Fed owes
Every dollar of assets is matched by a liability, and the liability mix is where the plumbing lives. Federal Reserve notes — physical currency — are the Fed's largest traditional liability. Bank reserves are the balances commercial banks hold at the Fed, created whenever the Fed buys assets. The overnight reverse repo facility (ON RRP) holds cash parked by money market funds. And the Treasury General Account (TGA) is the federal government's checking account. These liabilities trade places constantly: when the Treasury spends from the TGA, reserves rise; when money funds move cash into RRP, reserves fall. Analysts track these swaps because reserves are the banking system's raw liquidity.
Why the size matters — and why it doesn't
A larger balance sheet means the Fed has absorbed more securities from private hands and created more central bank money. But central bank money is not spendable money: as the aggregates explainer covers, reserves sit outside M2 entirely. The sheet's size matters mainly through longer-term interest rates (the point of QE), through the income the Fed remits to the Treasury (which turned negative when rates rose after 2022 — the Fed books the shortfall as a "deferred asset" rather than receiving a bailout), and through how much liquidity cushion the banking system has, which sets the practical floor for quantitative tightening.
How to read it
Three habits serve well. Watch reserves, not just totals — the same-sized sheet can carry very different reserve levels depending on the TGA and RRP. Distinguish policy moves from plumbing: a spike in discount window borrowing (March 2023) is a stress signal; a TGA rebuild after a debt ceiling episode is mechanics. And never map balance sheet growth one-for-one onto M2 — the 2010s proved the mapping loose, and anyone who traded on "balance sheet up, inflation next" spent that decade wrong. The balance sheet tells you what the Fed is doing; the money aggregates tell you what the banking system is doing with it.
Related reading
Quantitative Easing and Tightening, Explained · How the Fed Sets Interest Rates · How Money Is Created