Yep. An important concept is a "margin call". Funds are allowed leverage but within limits, and when the value of their assets (e.g. bonds) decreases then the l

Yep. An important concept is a "margin call". Funds are allowed leverage but within limits, and when the value of their assets (e.g. bonds) decreases then the leverage can increase. They need to put up more collateral (e.g. cash) to reduce the leverage to within agreed limits. But suppose that many funds are in the same situation at the same time! Now that collateral is more expensive and the leveraged assets are worth less. This can lead to collapses across the sector, which the BoE is very keen to prevent. Hence they intervened to prop up the assets.