Bank of England to Treasury, House of Commons




LDI strategies enable DB pension funds to use leverage (i.e. to borrow) to increase their
exposure to long-term gilts, while also holding riskier and higher-yielding assets such as
equities in order to boost their returns. The LDI funds maintain a cushion between the
value of their assets and liabilities, intended to absorb any losses on the gilts. If losses
exceed this cushion, the DB pension fund investor is asked to provide additional funds
to increase it, a process known as rebalancing. This can be a more difficult process for
pooled LDI funds, in part because they manage investment from a large number of small
and medium sized DB pension funds.

Diagram 1 gives a stylised example of how the gilt market dynamics last week could
have affected a DB pension fund that was investing in an LDI fund. In this illustrative and simplified example, the left hand side of the diagram shows that the scheme is underfunded (in deficit) before any change in gilt yields, with the value of its assets lower than
the value of its liabilities. More than 20% of UK DB pension funds were in deficit in August
2022 and more than 40% were a year earlier. In this example, the fund is holding growth
assets to boost returns and has also invested in an LDI fund to increase holdings of longterm gilts, funded by repo borrowing at 2 times leverage (i.e. half of the holding of gilts in
the LDI fund is funded by borrowing). The cushion (labelled ‘capital’) is half the size of
the gilt holdings.

The right hand side of the diagram shows what would happen should gilt yields rise (and
gilt prices fall). The value of the gilts that are held in the LDI fund falls, in this example by
around 30%. This severely erodes the cushion in the LDI fund. If gilt prices fell further, it
would risk eroding the entire cushion, leaving the LDI fund with zero net asset value and
leading to default on the repo borrowing. This would mean the bank counterparty would
take ownership of the gilts. It should be noted that in this example, the DB pension fund
might be better off overall as a result of the increase in gilt yields. This is because the
market value of its equity and shorter-term bond holdings (‘other assets’) would not fall
by as much as the present value of its pension liabilities, as the latter are more sensitive
to long-term market interest rates. The erosion of the cushion of the LDI fund would lead the LDI fund either to sell gilts to reduce its leverage or to ask the DB pension fund
investors to provide additional funds.

In practice, the move in gilt yields last week threatened to exceed the size of the cushion
for many LDI funds, requiring them to either sell gilts into a falling market or to ask DB
pension plan trustees to raise funds to provide more capital.

Author(s): Sir John Cunliffe, Deputy Governor, Financial Stability

Publication Date: 5 Oct 2022

Publication Site: UK Parliament