Rating Effects on Funding Costs

Why Ratings Can Change Funding Costs

A financial-strength rating can affect the terms on which an insurer or other borrower raises debt. A rating level may influence the spread investors require, the fees or covenants attached to an issue, and whether a particular funding market is available at all. A rating change can therefore affect the cost of planned borrowing even when it does not alter the coupon on debt already outstanding.

These effects are not a universal schedule: a rating category does not imply one fixed spread for every issuer or debt instrument. Funding costs also depend on such features as term, currency, issue size, market conditions, and the borrower’s specific circumstances. For analysis, management should use stated or supportable hypothetical terms for each scenario, then compare them on a consistent basis. The methods here are aligned with the CAS Exam 9 (Risk Management for Actuaries) syllabus.

Definition: A borrowing spread is the margin added to a reference or benchmark rate to determine a debt instrument’s interest rate. If the benchmark rate is $b_t$ in period $t$ and the spread is $s_t$, the period’s coupon rate is $b_t+s_t$, subject to the contract’s conventions. A rating-related funding-cost effect is the change in interest, fees, or other specified financing costs between rating scenarios, holding the comparison assumptions consistent.

The distinction between a spread and a total coupon matters. If the benchmark rate is the same in two scenarios, the difference in their coupon rates is the difference in spreads. If the benchmark changes as well, the full coupon difference must be calculated; it is not enough to compare spreads alone. Similarly, a change in a rating does not automatically change every existing debt payment. The contract determines whether an outstanding instrument reprices. Fixed-rate debt without a rating-related repricing provision retains its stated coupon under the assumptions used here.

Present Value of Incremental Spread Cost

Consider a hypothetical bullet borrowing with principal $P$ remaining constant over $n$ annual interest periods. Assume annual interest is paid at each year-end, the benchmark rate is unchanged between scenarios, and the spread increases by a constant amount $\Delta s$. Let $i$ be the effective annual rate used to discount the incremental payments. The increase in annual interest is $P\Delta s$, so the present value of the incremental spread cost is:

\operatorname{PV}(\text{incremental spread cost}) = P\Delta s \sum_{t=1}^{n}(1+i)^{-t} = P\Delta s\frac{1-(1+i)^{-n}}{i}.

This calculation assumes constant principal, annual end-of-year payments, a constant spread difference, and a constant annual discount rate. The formula does not directly apply to amortizing principal, irregular payment dates, changing spreads, or a different payment frequency without adjustment. In those cases, calculate each incremental payment using the balance and terms for its period, discount it to the valuation date, and sum the present values.

Justification: The incremental payment at the end of year $t$ is $P\Delta s$, with present value $P\Delta s(1+i)^{-t}$. The sum of discount factors is a finite geometric series with first term $(1+i)^{-1}$ and common ratio $(1+i)^{-1}$. Thus, for $i\ne 0$, its sum is $\bigl[1-(1+i)^{-n}\bigr]/i$. If $i=0$, the limiting value is $n$, so the present value is $nP\Delta s$.

An upfront fee is already measured at the valuation date if it is paid immediately, so it is added without discounting. A fee paid later must instead be discounted to the valuation date. When a rating scenario changes which borrowing sources are available, calculate the cost on each available portion of principal; do not assume that all funding remains available on the same terms.

Worked Example: A Rating Change Affects New Debt

A hypothetical insurer plans to issue $12,000,000 of three-year bullet debt. The benchmark rate is unchanged between two rating scenarios, and annual interest is paid on constant principal. The spread is 1.40% in Scenario A and 1.85% in Scenario B. There are no fees. Use an effective annual discount rate of 4.00%. Find Scenario B’s incremental present-value interest cost and state what happens to existing fixed-rate debt that has no rating-related repricing provision.

Method and assumptions. Compare only the spread difference because the benchmark is common. Principal remains $12,000,000 for three annual interest payments, all at year-end. The discount rate is 4.00% effective annually.

Step 1: Find the spread increase. The spread difference is $1.85\%-1.40\%=0.45\%=0.0045$. The annual incremental interest is:

\$12{,}000{,}000(0.0045)=\$54{,}000.

Step 2: Discount the three annual payments. Using the annuity formula without rounding the factor before multiplication:

\$54{,}000 \left[ \frac{1-(1.04)^{-3}}{0.04} \right] = \$54{,}000(2.7750910332\ldots) = \$149{,}854.92.

The present value of Scenario B’s incremental spread cost is $149,854.92, rounded to cents. Under the stated contract assumption, the existing fixed-rate coupon does not change. The conclusion would differ only if that debt’s terms provided for repricing or another payment change.

Check. The undiscounted increase is $3(\$54{,}000)=\$162{,}000$. A positive discount rate makes the present value less than $162,000, consistent with $149,854.92. The common mistake avoided is applying the new spread to all outstanding debt without checking its contract.

Compare Spread, Fees, and Funding Terms Together

A funding choice should be compared using all cost components included in the decision, not spread alone. For a simple bullet issue with an upfront fee, a useful present-value comparison is the present value of spread payments plus the fee. If the benchmark and principal are identical across choices, the common benchmark interest does not affect which choice has the lower cost; it can be excluded from the incremental comparison. This cancellation is not valid when the benchmark exposure differs between choices.

A practical comparison follows four steps: define the amount and term being funded; identify the annual spread cost under each choice; add fees and any other specified financing costs at their payment dates; then compare present values using a common valuation date and discount basis. If one scenario provides less funding at the quoted terms, include the cost of the alternative source needed to cover the shortfall. If no alternative is available, the decision is not simply a comparison of two prices: the financing need may be unmet.

Worked Example: Compare Two Funding Offers

A hypothetical insurer needs $10,000,000 of four-year bullet funding. Offer A has a spread of 1.30% and an upfront fee of 0.30% of principal. Offer B has a spread of 1.50% and an upfront fee of 0.20%. The benchmark is common, principal is constant, and annual interest is paid at year-end. Use a 4.00% effective annual discount rate. Which offer has the lower present-value spread-and-fee cost, and by how much?

Method and assumptions. Compare Offer B with Offer A. The common benchmark cancels. Both offers fund the same principal for the same four years, and each fee is paid immediately. The comparison includes only spread payments and the stated upfront fees.

Step 1: Calculate annual spread costs. Offer A costs $\$10{,}000{,}000(0.0130)=\$130{,}000$ per year. Offer B costs $\$10{,}000{,}000(0.0150)=\$150{,}000$ per year. Offer B therefore has an additional annual spread cost of $\$20{,}000$.

Step 2: Find the present value of the additional spread cost.

\$20{,}000 \left[ \frac{1-(1.04)^{-4}}{0.04} \right] = \$20{,}000(3.6298952259\ldots) = \$72{,}597.90.

Step 3: Compare the upfront fees. Offer A’s fee is $0.0030(\$10{,}000{,}000)=\$30{,}000$. Offer B’s fee is $0.0020(\$10{,}000{,}000)=\$20{,}000$. Offer B saves $10,000 in fees.

Step 4: Combine the differences. Offer B’s net incremental present-value cost is $\$72{,}597.90-\$10{,}000=\$62{,}597.90$. Therefore, Offer A has the lower present-value spread-and-fee cost by $62,597.90.

Check. Offer B’s spread is higher, but its fee is lower; the fee saving reduces, rather than reverses, the spread-cost disadvantage. The common mistake avoided is selecting the lower-fee offer without valuing the recurring spread difference.

When a Rating Change Alters Market Access

A rating scenario may affect more than the price of one unchanged borrowing source. It may alter the amount investors will provide, the type of facility available, or the terms required for a portion of the funding. A sound comparison represents each available source separately, with its own principal amount, spread, term, and fees. Any difference in funding access should be made explicit rather than hidden inside an assumed average spread.

The following example treats the funding terms as hypothetical scenario assumptions, not as a universal relationship between a rating and a market price. It compares a fully available base scenario with a second scenario in which part of the borrowing must be obtained from a more expensive source.

Worked Example: Include a More Expensive Replacement Facility

A hypothetical borrower requires $16,000,000 for two years. In Scenario A, the full amount is available as bullet debt at a 1.80% spread. In Scenario B, $12,000,000 is available at a 2.30% spread, while the remaining $4,000,000 must be borrowed through a facility at a 4.00% spread. The facility has an upfront fee of 0.50% of its principal. The benchmark is unchanged, interest is annual on constant principal, and the effective annual discount rate is 5.00%. Find Scenario B’s additional present-value spread-and-fee cost.

Method and assumptions. Calculate annual spread costs separately for each funded portion, then compare Scenario B with Scenario A. Both scenarios have two year-end interest payments. The facility fee is paid immediately. The benchmark and all other costs are common or excluded by assumption.

Step 1: Calculate Scenario A’s annual spread cost.

\$16{,}000{,}000(0.0180)=\$288{,}000.

Step 2: Calculate Scenario B’s annual spread cost. The first portion costs $\$12{,}000{,}000(0.0230)=\$276{,}000$ per year. The facility portion costs $\$4{,}000{,}000(0.0400)=\$160{,}000$ per year. Thus, Scenario B’s total annual spread cost is $\$276{,}000+\$160{,}000=\$436{,}000$, or $\$436{,}000-\$288{,}000=\$148{,}000$ more per year than Scenario A.

Step 3: Discount the additional interest.

\$148{,}000 \left[ \frac{1-(1.05)^{-2}}{0.05} \right] = \$148{,}000(1.8594104308\ldots) = \$275{,}192.74.

Step 4: Add the immediate fee. The facility fee is $0.0050(\$4{,}000{,}000)=\$20{,}000$. Scenario B’s total additional present-value cost is $\$275{,}192.74+\$20{,}000=\$295{,}192.74$.

Check. Scenario B’s annual spread increase is positive, and it also has a positive fee, so its additional cost must be positive. The calculation gives $295,192.74. The common mistake avoided is applying the facility spread to all $16,000,000 or, conversely, forgetting the facility portion when comparing with Scenario A.

Interpretation and Common Traps

A present-value result is conditional on its assumptions. It measures the value, at a stated valuation date, of the specified incremental payments using the chosen discount rate. It is not automatically the borrower’s total economic cost, nor does it establish that one rating scenario will occur. If the funding term, principal profile, benchmark exposure, fees, or availability differs from the assumptions, the comparison should be revised.

A rating improvement can reduce the spread on new borrowing, but its economic value depends on how much debt is actually issued and for how long. A spread reduction on a small, short-term issue can be worth less than a modest fee or a change in access to another funding source. Conversely, a downgrade need not increase payments on fixed-rate debt that has no applicable repricing provision. The relevant exposure is the debt whose contractual terms or future issuance costs are affected.

Confusing basis points with percentage points. One basis point is 0.01 percentage point, or 0.0001 as a decimal. Thus, 45 basis points is 0.0045, not 0.45.
Comparing spreads when benchmarks differ. If benchmark rates differ, compare total interest rates or otherwise include the benchmark change.
Ignoring fee timing. An immediate fee is added at its amount; a later fee must be discounted.
Rounding an annuity factor too early. Retain full precision in the factor and round the final dollar result to cents.
Applying a new spread to existing debt indiscriminately. Check the contract and the actual debt being issued or repriced.
Assuming market access is unlimited. If only part of the required amount is available at one price, model the remaining amount separately or state that the funding need cannot be met under the scenario.

Key takeaway: A disciplined rating-related funding comparison isolates the cash flows that actually change, converts spread differences correctly, includes fees and funding access where specified, and discounts each payment consistently. The result is a scenario-based cost comparison, not a universal price assigned to a rating category.

Check Your Understanding

For each problem, assume the stated terms are hypothetical, annual interest is paid at year-end on constant bullet principal, and the benchmark is common unless stated otherwise. Round dollar answers to cents.

A borrower issues $5,000,000 of two-year debt. A rating scenario increases the spread by 0.30%, with no fee change. The effective annual discount rate is 4.00%. Find the incremental present-value interest cost. (Answer: $28,291.42)
A hypothetical insurer borrows $9,000,000 for four years. A rating change increases the spread by 0.20% and adds an immediate fee of 0.10% of principal. At a 4.00% effective annual discount rate, find the total incremental present-value cost. (Answer: $74,338.11)
For a three-year $6,000,000 issue, Offer A has a 1.40% spread and a 0.20% upfront fee. Offer B has a 1.65% spread and no fee. Principal and benchmark are common, and the discount rate is 5.00%. Which offer is less costly on a present-value spread-and-fee basis, and by how much? (Answer: Offer A, by $28,848.72)
A borrower needs $20,000,000 for two years. Scenario A funds all of it at a 1.60% spread. Scenario B funds $14,000,000 at a 2.00% spread and $6,000,000 at a 3.00% spread, with an immediate fee of 0.25% on the $6,000,000 portion. Find Scenario B’s additional present-value spread-and-fee cost at a 4.00% effective annual discount rate. (Answer: $279,053.25)
A company has $25,000,000 of existing fixed-rate debt with no rating-related repricing provision. A rating scenario increases the spread on new borrowing by 0.40%. The company plans to issue $7,000,000 of new three-year bullet debt; the benchmark is unchanged, there are no fees, and the effective annual discount rate is 4.00%. Find the incremental present-value cost and state whether the existing fixed-rate coupon changes under these assumptions. (Answer: $77,702.55; the existing fixed-rate coupon does not change)

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