Quantitative Easing

Quantitative easing is the Fed buying Treasuries and mortgage bonds with newly created bank reserves, expanding the balance sheet to push down long-term rates when the overnight rate is already at zero. The balance sheet went from roughly $900 billion to $9 trillion; the unwind is the part nobody queues up for.

Macro & PolicyLast reviewed 2026-10-08

What it is

Quantitative easing (QE) is the Federal Reserve buying longer-term securities, mostly Treasuries and agency mortgage-backed securities, and paying for them with newly created bank reserves. The goal is to push down long-term interest rates and mortgage rates when the fed funds rate is already at the zero lower bound and cannot be cut further.

In the US it has run three times: 2008-2014 (the balance sheet grew from roughly $900 billion to $4.5 trillion), and the pandemic round in 2020 (to roughly $9 trillion by 2022). The reverse, quantitative tightening, began in June 2022 and unwound the peak. QE is not money printing into your checking account; it is a swap of assets for reserves that changes the price of duration across the market.

Key takeaways

QE is the Fed buying Treasuries and mortgage bonds with newly created reserves, pushing down long-term rates.
The balance sheet grew from roughly $900 billion (2008) to $4.5 trillion (2014) to roughly $9 trillion (2022).
The mechanism is the portfolio balance channel: removing duration pushes investors into credit, equities, and mortgages.
QE runs when the fed funds rate is at zero; it is the second lever, not the first.
Quantitative tightening (from June 2022) is the unwind, and it is the part that moves mortgage rates back up.

How it works

The mechanics are a swap, not a helicopter drop. The Fed creates bank reserves (a liability on its own balance sheet) and uses them to buy Treasuries and agency MBS from the market (an asset swap that removes duration from investor portfolios). Investors who sold duration reinvest into corporate credit, equities, and mortgage borrowing, which pushes those prices up and yields down. This is the portfolio balance channel, and it is the mechanism QE actually runs on; the reserves themselves mostly sit at the Fed earning interest.

The effect shows up at the long end, which is the part the fed funds rate cannot reach directly. Mortgage rates fell to record lows under the pandemic QE (the 30-year fixed touched roughly 2.65% in January 2021), and corporate bond spreads compressed in every round. The 10-year Treasury yield is the price of duration, and QE is the largest buyer of duration in the market.

The unwind is the mirror image. Quantitative tightening (running since June 2022) lets maturing securities roll off without reinvestment, returning duration to the market and pushing long-term yields up; the 2013 taper tantrum (Bernanke's May comments moved the 10-year up roughly a point in months) is the preview of what merely announcing the unwind does.

Why it matters

QE is why the 30-year mortgage hit 2.65% in January 2021 and why refinancing was free money for two years, and it is why the unwind pushed mortgage rates back above 6%. The portfolio effects are direct: the duration the Fed removed pushed investors into equities and credit, which is a fair description of the 2009-2021 bull market in everything. The 2013 taper tantrum showed the announcement alone moves the long end by a point.

I watched a colleague named Brent (yes, that Brent) blame QE for everything from home prices to avocado toast without being able to describe what it buys. The mechanism is an asset swap; the results are real, and so is the unwind.

The highest-leverage thing most Americans can do is understand which lever is running: fed funds moves the short end, QE moves the long end, and your mortgage prices off the long end. Price the mortgage side with the mortgage amortization calculator and the bond side with the bond yield calculator.

Real-world examples

The balance sheet, 2008 to 2022

The Fed balance sheet stood at roughly $900 billion in August 2008. QE1 through QE3 (2008-2014) took it to roughly $4.5 trillion; the pandemic round (March 2020 onward) took it to roughly $9 trillion by 2022; and quantitative tightening from June 2022 unwound the peak toward $6.6 trillion. Each expansion pushed the long end down and asset prices up; each unwind ran the reverse. The balance sheet is the second lever, and it moves when the first (fed funds) is out of room.

The 2.65% mortgage

Under the pandemic QE, the Fed bought roughly $40 billion of agency MBS a week, and the 30-year fixed fell to roughly 2.65% by January 2021, the lowest on record. A $400,000 mortgage refinanced from 4.5% to 2.75% saved roughly $450 a month, roughly $162,000 over the life of the loan. The buyer of duration set the price of duration, and the mortgage market is where the duration lives. The unwind since 2022 has run the arithmetic backward, with the 30-year back above 6%.

The 2013 taper tantrum

In May 2013 Bernanke said the Fed might slow its bond purchases later that year, without buying or selling a single bond. The 10-year Treasury yield rose roughly one percentage point in three months (from about 1.7% to 2.7%), and mortgage rates followed within a point of it. The announcement of the unwind moved the long end before the unwind happened, which is the market pricing the return of duration. QE works on expectations as much as on flows, in both directions.

Common mistakes

Mistake: Calling QE money printing into the real economy.

Why it bites you: QE is an asset swap for bank reserves that changes the price of duration; the reserves mostly sit at the Fed earning interest. The helicopter-money version is fiscal, and it has a different name.

Mistake: Assuming QE causes consumer inflation one for one.

Why it bites you: The 2008-2014 rounds ran alongside roughly 1.5% CPI inflation for a decade; the pass-through ran to asset prices and long-end yields, not groceries. The 2021-2022 inflation had fiscal stimulus and supply chains doing most of the work.

Mistake: Ignoring the unwind when refinancing or buying bonds.

Why it bites you: QT returns duration to the market and pushes long-term yields up; the 30-year mortgage went from 2.65% to above 6% through the unwind. The 2013 tantrum priced it a point in three months.

Mistake: Crediting QE alone for the bull market.

Why it bites you: QE ran alongside fiscal stimulus, buybacks, and earnings growth, and the attribution is a bar fight rather than a regression. The portfolio balance channel is real; it is not the only buyer in the market.

Ivy's take

I spent an evening with the Fed balance-sheet history and the taper-tantrum timeline so you do not have to, and QE is the second lever in a two-lever system: fed funds moves the short end, QE moves the long end, and the mortgage market lives at the long end. I ran the 2008-2022 balance-sheet arithmetic against CPI and asset prices, and the honest summary is that QE moved the price of duration more than the price of bread. Brent blamed it for avocado toast, which is the least falsifiable sentence in macroeconomics. My rule: when the Fed is buying duration, refinance; when it is unwinding, do not fight the long end. The 2.65% mortgage was the lever, and the 6% one is too.

Related jargon, defined

Balance sheet: The Fed holdings of Treasuries and MBS; grew from roughly $900 billion to $9 trillion across the QE rounds.
Bank reserves: Deposits banks hold at the Fed; what QE creates to pay for the bonds.
Agency MBS: Fannie, Freddie, and Ginnie mortgage bonds; the QE purchase that sets mortgage rates.
Portfolio balance channel: The mechanism: removing duration pushes investors into credit and equities, lowering yields.
Quantitative tightening: The unwind: letting maturing bonds roll off without reinvestment, returning duration to the market.
Taper tantrum: The 2013 yield spike from merely announcing a slower pace of purchases.

Frequently asked questions

What is quantitative easing in simple terms?+

It is the Fed buying longer-term Treasuries and mortgage bonds with newly created bank reserves to push down long-term rates. It runs when the fed funds rate is already at zero and cannot be cut further.

Does QE cause inflation?+

Not one for one: the 2008-2014 rounds ran alongside roughly 1.5% CPI inflation. The pass-through runs to asset prices and long-term yields; the 2021-2022 inflation had fiscal stimulus and supply chains doing most of the work.

How does QE affect mortgage rates?+

Directly: the Fed buys agency MBS, which is exactly the market mortgages price from. The pandemic QE took the 30-year fixed to a record 2.65% in January 2021, and the unwind pushed it back above 6%.

What is the difference between QE and quantitative tightening?+

QE adds duration to the Fed balance sheet and removes it from the market, lowering long-term yields; QT does the reverse. The 2013 taper tantrum showed the announcement of the unwind alone moves the long end by a point.

Is QE still running?+

The pandemic round ended and quantitative tightening began in June 2022, letting maturing bonds roll off. The balance sheet peaked near $9 trillion and has unwound from there; the lever reverses in the next crisis.

Disclaimer: This information is general in nature and does not constitute financial or legal advice. Always consult a qualified professional for your specific situation.

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