The Bank of England published Staff Working Paper No. 1,108 examining how preferred-habitat demand affects the transmission of quantitative easing (QE) and quantitative tightening (QT) through gilt markets. Using granular Bank of England QE and QT auction data alongside bond-level secondary market transaction data, the authors find that preferred-habitat investors such as pension funds and insurance companies were associated with less elastic bidding in QE auctions, while no significant preferred-habitat demand pressures are detected in QT auctions. To explain the asymmetry between QE and QT, the paper extends the constant-elasticity preferred-habitat demand model of Vayanos and Vila (2021) by allowing demand elasticity to depend on the amount of bond supply available to investors. The reduced role of the preferred-habitat channel during QT is presented as consistent with increased UK government bond issuance after the Covid-19 pandemic. The analysis is published as research in progress to elicit comments and debate and does not represent Bank of England policy.