我们应该如何看待量化紧缩政策的结束

24 October 2025 Richard de Chazal, CFArdechazal@williamblair.com+44 20 7868 4489 Economics WeeklyHow Should We Think About the End ofQuantitative Tightening Louis Mukamalmukama@williamblair.com+1 312 364 8867 William Blair Our long-stated plan is to stop balance sheet runoffwhen reserves are somewhat above the level wejudge consistent with ample reserve conditions. Wemay approach that point in coming months, andwe are closely monitoring a wide range of indica-tors to inform this decision. Some signs have begunto emerge that liquidity conditions are graduallytightening, including a general firming of reporates along with more noticeable but temporarypressures on selected dates. The Committee’s planslay out a deliberately cautious approach to avoidthe kind of money market strains experienced inSeptember 2019. that a lower-term premium is where we should belooking for its impact. 3)The volatility or signaling channel –Providing moreliquidity to markets helps calm volatility, but QE alsois intended as a firm message to markets that the Fedwill keep rates low for as long as necessary to preventdeflation and keep the economy rolling. The processalso involves reinforcing that message to marketparticipants through public addresses, remindinginvestors that the Fed won’t suddenly reverse courseand raise rates again as long as LSAPs are still beingcarried out. – Chair Jerome H. Powell, “Understanding the Fed’sBalance Sheet,” speech delivered October 14, 2025 Through these channels, QE also helps depreciate theexchange rate, which supports stronger export growthas well as the equity market, by boosting the net presentvalue of those assets via a lower discount rate. Last week, Chair Powell announced that the Fed is gettingclose to ending quantitative tightening (QT), which beganin June 2022. During this cycle, the Fed has managed toreduce the size of its balance sheet by $2.3 trillion, to $6.6trillion, after ballooning to $8.9 trillion. The decision toend QT comes as emerging stress in the financial systemhas been signaling that the level of reserves, while still in“ample” territory, is moving closer to “scarce.”In this Eco-nomics Weekly, we discuss how QT has played out so farand what its ending might mean for financial markets. Shouldn’t QT Be the Reverse of QE? Quantitative tightening would seemingly be the reverseof QE: bank reserves created out of thin air are extin-guished, the duration of debt in the market starts to riseagain, and the Fed signals that it will move away fromeasing and potentially back toward a tightening stance. Indeed, the Fed previously believed that it could not startto lower interest rates as long as QT was still being car-ried out. It felt this would be seen as effectively pullingthe interest rate lever in one direction while pushing thebalance sheet lever in the other, which might be viewedas counterproductive. In the end, the Fed seems to haveovercome its cognitive dissonance, as this is exactly whatit has been doing over the last few years. The QE Channels When the Fed undertakes QE (or large-scale asset pur-chases [LSAPs]), it purchases assets (mostly Treasurysand agency mortgage-backed securities) in the secondarymarket from financial institutions that are eligible to holdreserve accounts at the Fed. To pay for those purchases, theFed simply credits those accounts with reserves—reservesthat it creates out of thin air. Meanwhile, as exhibit 1 shows, QT1 (October 2017 toSeptember 2019) has also been notably different fromQT2 (June 2022 to present). The Fed believes that LSAPs impact the economy andfinancial markets through three main channels: 1)The liquidity channel –The agency acts as a lenderof last resort and puts cash in the hands of financialinstitutions that might be liquidity constrained, low-ering the risk of default and market contagion. 2)The duration/portfolio balance channel–The Fedtypically controls the short end of the yield curve, butQE enables it to impact the long end of the curve byreducing the supply of longer-term Treasury securi-ties in the open market, which helps raise the priceand lower the demanded term premium. It believes William Blair During QT1, which we would dub a “normal” QE, the Fedvery much followed this QE reversal pattern. Treasurys andother securities that matured were not reinvested, shrink-ing the asset side of the balance sheet, while correspondingbank reserves on the liability side also shrunk. The ON RRP facility allows financial market participants,such as money market funds, to swap cash for Treasurysecurities held at the Fed, which the Fed repos back thenext day. In so doing, it allows the Fed to add or subtractliquidity from the system to manage and maintain the fedfunds policy rate at its desired target level. It also effec-tively acts as a floor for the funds rate—why would youtake the risk of lending to another financial institution fora lower rate than you would earn lending that cash to theFed entirely risk-free? T