What it means
Big holders of bonds, such as pension schemes and insurers, often own securities they intend to keep for years. Other market participants sometimes need to borrow those exact bonds temporarily, usually to settle a trade or to establish a short position (a bet that the price will fall).
Cash for bond lending is the transaction that connects the two sides. The structure matters because it changes who takes which risk.
The bond lender gives up the security temporarily but holds cash worth slightly more than the bond, so if the borrower fails the lender can keep the cash and buy a replacement. The borrower gets the bond it needs and earns a return on its posted cash through the rebate.
The economics come from two rates. The lender invests the cash collateral and earns a reinvestment rate, then pays the borrower the agreed rebate rate, and the spread between them is the lending fee.
For a bond in heavy demand the rebate falls, widening the spread; for an easily available bond the rebate rises and the spread narrows almost to nothing. Collateral is deliberately set above the value of the bond, a cushion known as a haircut or margin, commonly in the region of 2% to 5% for government bonds.
Positions are marked to market daily and extra cash is called for or returned as the bond's price moves. That daily discipline is what makes the arrangement workable at scale.
The important nuance is that the lender takes reinvestment risk on the cash. If the collateral is invested in instruments that fall in value or cannot be sold quickly, the lender may be unable to return the cash on demand even though the bond itself was never at risk, which is why conservative lenders restrict reinvestment to very short, high-quality instruments.
In practice
Real-world examples.
Example
An insurance company holds a large block of long-dated government bonds to match its liabilities. It lends them against cash collateral through its custodian and earns roughly $600,000 a year in spread income, which it uses to offset its investment management costs.
Example
A hedge fund wants to short a specific corporate bond ahead of an expected credit downgrade. It borrows the bond against cash, sells it in the market, and later buys it back and returns it, paying the lending spread as the cost of the position.
Example
A dealer has promised to deliver a bond it does not yet hold and faces a settlement failure. It borrows the exact security against cash for five days, settles the trade on time, and treats the small spread cost as cheaper than the penalty for failing.
Formula
Calculation
Lending Spread = Reinvestment Rate on Cash Collateral - Rebate Rate Paid to Borrower
Lending Revenue = Cash Collateral x Lending Spread x (Days / 360)
A pension scheme lends government bonds with a market value of $50,000,000 and receives cash collateral of $51,000,000, which represents a 2% haircut. For simplicity the fee is calculated on the $50,000,000 of lent value. The scheme invests the cash at 5.00% a year and pays the borrower a rebate of 4.60% a year.
The spread is 5.00% - 4.60% = 0.40%. On $50,000,000 that is $200,000 for a full year. The loan runs for 90 days, so the revenue is $200,000 x 90 / 360 = $50,000 earned on bonds the scheme was holding regardless.Case study
Seen in the real world.
Meridian Harbour Pension Trust is an illustrative and entirely fictional scheme used here to show both sides of the trade. The trust held $800,000,000 of government bonds as a long-term match for its pension promises and lent about $300,000,000 of them at any one time against cash collateral, earning a spread of roughly 0.35% and adding close to $1,000,000 a year of income.
During a period of market stress the trust's investment committee reviewed where the cash collateral was being invested and found that part of it sat in instruments maturing in several months rather than several days. Borrowers were returning bonds and asking for their cash back faster than those instruments could be sold without a loss.
In this fictional case the committee rewrote its collateral policy to allow only overnight and one-week instruments, accepting a lower reinvestment rate and a thinner spread. Income fell by about a third, and the programme became something the trustees could sleep through, which was the point of the exercise.
Watch out
Common mistakes.
- Assuming cash collateral removes all risk. It removes borrower default risk on the bond, but it creates reinvestment risk on the cash, which is a different exposure that needs its own policy.
- Thinking the lender loses the income on the bond. The lender is contractually made whole for any coupon paid while the bond is out on loan, so the economic interest stays with the lender.
- Treating the rebate as the lender's cost of borrowing. The rebate is interest paid to the borrower on its own cash, and the lender's real economics are the spread between reinvestment and rebate.
Questions
People also ask.
Who keeps the bond's coupon during the loan?
The borrower receives it from the issuer but must pass an equivalent amount back to the lender, so the lender ends up no worse off.
Why is collateral worth more than the bond?
The excess, called a haircut, gives the lender a cushion to buy a replacement bond if the borrower fails and prices have moved against it.
Can the lender recall the bond early?
Yes, most arrangements are open and the lender can recall the security at short notice, which is exactly why the cash collateral must be invested in instruments that can be liquidated quickly.
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