How Central Banks Affect Bond Markets

They are not elected. They are appointed. And their meetings, held several times a year in conference rooms in Washington, Frankfurt, London, and Tokyo, are the most watched events in all of global finance. They are central bankers. And understanding how they interact with bond markets is perhaps the most important piece of macro knowledge available to any trader.

The moment the Fed raises its rate by 0.25%, every short-term Treasury yield adjusts almost immediately to reflect the new level. 3-month T-bill yields, 6-month yields, 2-year note yields, all shift almost instantaneously.

The long end of the curve, the 10-year and 30-year yields, is influenced by the Fed but not directly controlled by it. Long rates are set by the market''s collective expectation about where short rates will average over the long term, overlaid with inflation expectations. The Fed influences these expectations through its communications but cannot dictate them. This is why the yield curve''s shape changes as the Fed moves.

The mortgage channel is the most immediate for most households. When the Fed raises rates, mortgage rates rise. A family that could afford a $400,000 home at 3% mortgage rates may only be able to afford a $280,000 home at 7%. Housing demand falls. Construction slows. Prices soften.

The corporate borrowing channel affects businesses. Companies borrow to invest and expand. When rates rise that borrowing costs more. Companies become more cautious about capital expenditure. Weaker companies with heavy existing debt loads see interest expenses rise and profits squeezed.

The equity channel works through valuations. Rising interest rates compress stock valuations through the discount rate mechanism. Lower equity prices reduce household wealth and can cause them to spend less.

The currency channel affects trade. Higher rates attract global capital seeking better returns, strengthening the currency. A stronger currency makes exports more expensive abroad, reducing demand. All of these channels operate simultaneously with variable and uncertain lags.

The Fed needed a new tool. What it deployed was quantitative easing. In QE the central bank creates new money and uses it to buy financial assets, primarily government bonds, directly from investors in the secondary market. By buying bonds it pushes bond prices up and yields down beyond what the policy rate alone could achieve.

The Fed, ECB, Bank of England, and Bank of Japan have all used QE extensively since 2008 and again during COVID. The unwinding of QE, called quantitative tightening or QT, reverses the process. The central bank allows bonds to mature without reinvesting the proceeds, putting upward pressure on yields. The combination of aggressive rate hikes and QT in 2022 to 2023 created one of the most severe bond market sell-offs in decades.

Forward guidance is the practice of communicating clearly about likely future policy decisions. When the Federal Reserve says it expects rates to remain elevated for an extended period it is not making a binding commitment. But it is shifting the market''s expectation about where rates are going, and because bond yields already price in expected future rates, the communication itself immediately affects yields.

A single adjective change in a Fed statement, from patient to vigilant, can move EUR/USD by 50 pips and the 2-year yield by 10 basis points in minutes. When central bank forward guidance is credible it can be almost as powerful as an actual rate move.

When it loses credibility, when a central bank signals one thing and does another, the consequences are sharp. The Bank of England in 2021 strongly signalled rate hikes and then failed to deliver, causing significant volatility in Gilt markets and damaging its credibility in a way that contributed to markets'' harsh reaction to subsequent UK fiscal announcements. The language tells you where the bond market is going before the decisions confirm it.