Know these first
- L3.6.04: Net interest income sensitivity
- L3.6.05: Economic value of equity sensitivity
Math Atoms
By the end you will be able to
- 1Lay an insurer's liability cash flows against its assets and name the reinvestment risk.
- 2Measure duration, PV01 and the duration gap of an insurer's balance sheet, book by book.
- 3Explain why a matched duration still loses own funds when rates move, using convexity and the guarantees.
- 4Apply the Solvency II rate shocks, judge a rebalancing, and approximate a run-off with a geometric series.
- 5Outline the matching adjustment and contrast insurer ALM with a bank's.
Why it matters
RiskAtoms Insurance SE owes €50.9bn to policyholders, some of it to annuitants who will be paid for another four decades. Its €54bn of bonds have almost the same duration as those promises: own funds move just €0.69m per basis point. Yet if rates fell 100bp, the solvency ratio would drop from 186% to 165%. Matching duration is where insurer ALM starts, not where it ends.
Core explanation
Promises decades long, bonds a few years long
Illustrative dataRiskAtoms Insurance SE's insurance book
The same composite European insurer as Modules 1.8 and 2.2, reporting in € millions at 31 December 2025: €70bn of assets, €9.0bn of non-life premiums, annuities, savings with guarantees and term business, a cat event set, a reinsurance programme and a Solvency II standard formula in outline (SCR €5,000m, own funds €9,300m, a ratio of 186%). Every line, event, bond, treaty and price is made up for teaching and seeded so it never changes; none is any insurer's data. The same book runs through every lesson in Module 3.8, so the figures agree.
This lesson relies on the book's illustrative euro zero curve (annual compounding, no extrapolation, no volatility or matching adjustment in the base), on best estimates that move with the curve while the risk margin and the time value of the guarantees are held, and on savings lapses that do not depend on rates. Own-funds changes are before tax.
Asset-liability management in a bank is about deposits that can leave and loans that reprice (L3.6.04: Net interest income sensitivity, L3.6.05: Economic value of equity sensitivity). In an insurer it starts from the liabilities: promises whose timing is fairly well known, often for decades, with options attached. The assets are chosen to meet them.
The cash flows
The bonds pay €63,205m in all, bunched in the first five years, and the last one matures in 2045. The liabilities pay €62,225m, running to 2069. The spikes in 2033 and 2037 are savings contracts maturing (€7,410m and €5,754m). €3,739m of payments (present value €1,845m) fall after the last bond has repaid: they will be met from money reinvested at rates no one knows today. That is reinvestment risk, and it is the reason cash-flow matching is the gold standard for annuities. Perfect matching is rarely possible: very long bonds are limited in supply, and the liability flows are themselves uncertain.
Duration and PV01, book by book
The usual compromise is to match value sensitivity rather than each cash flow. Revalue every book on the curve moved up and down a little: that gives an effective duration that works even for the savings book, whose cash flows themselves depend on rates.
| Book | Best estimate | Duration | Convexity |
|---|---|---|---|
| Annuities in payment | 19,928 | 9.24 | 144.1 |
| Savings with guarantees | 23,259 | 3.25 | 143.6 |
| Term assurance | −529 | −1.50 | −58.8 |
| Income protection | 50 | 16.48 | 289.4 |
| Non-life claims and premiums | 8,213 | 2.32 | 10.5 |
| All liabilities | 50,922 | 5.51 | 124.6 |
Annuities are the long book (9.24 years). Savings are short (3.25 years) because policies mature or are surrendered, but they are as convex as the annuities: that is the guarantee. Term assurance has a negative best estimate (future premiums exceed claims), so its value rises when rates rise and its duration is negative. On the whole balance sheet, the bonds' duration is 5.03 years and the liabilities' 5.48 years; the PV01s are €27.19m and €27.88m per basis point, and the duration gap is −0.13 years. By the measure of L3.6.05: Economic value of equity sensitivity, that is close to matched.
Matched, and still exposed
| Parallel shift | Bonds | Best estimates | Own funds |
|---|---|---|---|
| -200bp | 5,952 | 7,645 | −1,692 |
| -150bp | 4,362 | 5,309 | −948 |
| -100bp | 2,842 | 3,289 | −447 |
| -50bp | 1,390 | 1,512 | −122 |
| +50bp | −1,331 | −1,310 | −21 |
| +100bp | −2,607 | −2,449 | −158 |
| +150bp | −3,831 | −3,430 | −402 |
| +200bp | −5,007 | −4,259 | −748 |
Own funds fall whichever way rates move: −€447m at −100bp and −€158m at +100bp. The liabilities are 2.9 times as convex as the bonds (124.6 against 43.5). Long annuities explain part of it. The rest is the savings guarantees (L3.8.08: Lapse and policyholder behaviour): when rates fall, more cohorts' guarantees bite and the liability grows faster than any bond; when rates rise, the crediting rate follows them up and the liability barely falls. The insurer has sold options, and sold options lose money in big moves either way. The capital requirement moves too: at −100bp the SCR rises by €353m, so the ratio falls to 165%.
The regulatory shocks
The standard formula does not use parallel shifts. It moves each zero rate by a relative amount that falls with maturity (Delegated Regulation 2015/35, Arts 166–167), with an up move of at least one percentage point and no down move on negative rates:
| Maturity | Base rate | Up factor | Up rate | Down factor | Down rate |
|---|---|---|---|---|---|
| 1 years | 2.00% | +70% | 3.40% | −75% | 0.50% |
| 2 years | 2.05% | +70% | 3.48% | −65% | 0.72% |
| 5 years | 2.25% | +55% | 3.49% | −46% | 1.22% |
| 10 years | 2.55% | +42% | 3.62% | −31% | 1.76% |
| 15 years | 2.70% | +33% | 3.70% | −27% | 1.97% |
| 20 years | 2.75% | +26% | 3.75% | −29% | 1.95% |
| 30 years | 2.80% | +25% | 3.80% | −28% | 2.02% |
| 50 years | 3.00% | +23% | 4.00% | −25% | 2.25% |
Both shocks are of similar size in basis points on this curve, and largest at the short end where the bonds are. Bonds lose €3,084m, best estimates fall €2,691m, so own funds lose €393m. The down shock costs only €87m. The interest rate charge is the larger, €393m, with the up scenario binding: the input to the market risk module in L3.8.12: Insurer investment risk and the ORSA.
Rebalancing: which target?
Suppose the investment team moves money from the 2-year government bonds into the 20-year ones. About €600m closes the PV01 gap (+€0.06m per bp), yet it raises the interest charge to €458m, because the up shock binds. Going the other way, €1,500m from 20-year into 2-year bonds, gives the smallest charge, €237m, with the up and down losses balanced (€231m and €237m), but own funds would then lose €657m if rates fell 100bp. The target depends on what the board wants to protect: the regulatory charge under the prescribed shocks, own funds in parallel moves, or the cash to pay annuities in thirty years. The Try it lets you explore the trade.
The matching adjustment, in outline
An insurer that holds bonds to maturity against predictable annuities is not exposed to their price swings in the way a trader is: it is exposed to default. The matching adjustment ( Directive 2009/138/EC, Arts 77b–77c) recognises this. With supervisory approval, it adds to the risk-free rate the assets' spread less a fundamental spread for default and downgrade. The conditions are strict: an assigned portfolio of fixed-cash-flow assets that replicates the liabilities, managed and ring-fenced separately, no future premiums, only longevity, expense, revision and mortality risk, and no policyholder options beyond a capped surrender value. A firm that breaks the conditions and cannot restore them within two months loses the adjustment for 24 months.
On the book, a spread of 1.20% less a fundamental spread of 0.45% gives 75bp. Discounting the annuities at the risk-free rate plus 75bp cuts their best estimate from €19,928m to €18,625m, €1,304m more own funds before tax. RiskAtoms does not use it in the base: its annuities are not backed by a ring-fenced matched portfolio, and its bond portfolio is far shorter than the annuities.
A bank's ALM and an insurer's
| Bank (Module 3.6) | Insurer (this book) | |
|---|---|---|
| Liabilities | Deposits, short, can run | Policies, long, mostly predictable |
| Typical gap | Assets longer than liabilities | Liabilities longer than assets |
| Rate risk measured as | NII and EVE sensitivity | Own funds and the solvency ratio |
| Options sold | Prepayment, deposit withdrawal | Guarantees, surrender, annuity options |
| Liquidity risk | Deposit run | Mass lapse, collateral calls on hedges |
Sort itBank or insurer?
Which balance sheet is each statement more typical of?
Its biggest rate worry is that rates fall and long promises become dearer to fund.
It reports how much net interest income changes over the next year if rates move.
Its liabilities can be withdrawn at a day's notice.
It must hold capital for an instantaneous relative shock to the whole risk-free curve under a prescribed table.
It can discount some liabilities at a rate that includes part of its assets' spread.
The formal version
On the book. Durations and convexities measured with ±10bp moves (M-B03: Taylor expansion), A = €54,000m, L = €50,922m:
The liabilities' duration here, 5.51, is the average of the slopes up and down; measured on a rise alone it is 5.48. The difference is the guarantee again: the liability is steeper on the way down. That is also why the Taylor estimate gets only part of the −100bp loss: convexity measured at today's rates understates how fast the options gain value as rates keep falling. Second order is a good guide for small moves and for bonds; for books with options, revalue.
A run-off as a geometric series. If a book pays next year and then a fixed fraction of the year before, its value on a flat rate , with , is a geometric series (M-A07: Geometric series), and so is its duration:
using , the derivative of the geometric series. Choose so the series pays the same total as the book, :
| C₁ | q | Flat rate | PV: series | PV: book | Duration: series | Duration: book | |
|---|---|---|---|---|---|---|---|
| Non-life claims | 2,796 | 0.627 | 2.05% | 7,106 | 7,112 | 2.59 | 2.56 |
| Annuities | 1,697 | 0.935 | 2.55% | 18,688 | 20,017 | 11.29 | 9.64 |
For the short-tail non-life claims, which settle by a roughly constant fraction each year, the shortcut is within 0.1% on value and 0.03 years on duration. For annuities it fails: deaths accelerate with age, so payments shrink slowly at first and then fast, and a geometric tail puts too much weight far out (11.3 years against 9.6). That is why insurers project annuity cash flows life by life.
Try it
Move money between the 2-year and the 20-year government bonds. Watch the PV01 of own funds go through zero, the binding shock switch from up to down, and the own-funds curve tilt. Can you find a position that is good on all three?
Try itLengthen or shorten the bonds
Today's portfolio.
A loss is a fall in own funds (bonds less best estimates; risk margin held, before tax). A negative loss is a gain. Today the charge is €393m and the up shock binds. Illustrative data, € millions.
Worked example
Rates fall 100bp
All figures from the book, € millions, before tax.
A 100bp parallel fall through RiskAtoms' balance sheet
Step 1 of 5- 1
Bonds
Each bond is revalued on the lower curve. The €54bn portfolio gains €2,842m, about 5.26%: a little more than duration × 1% (5.04%) because bonds are convex.
21 points of ratio from a 100bp move, with a duration gap of −0.13 years. The fall in own funds is a convexity loss; the rise in the SCR is the guarantees and longevity costing more at lower rates.
Regulatory lens
Solvency II values liabilities on a risk-free curve published by EIOPA, which can include a volatility adjustment, or, with approval, a matching adjustment (Directive 2009/138/EC, Arts 77b–77d). A firm using either must assess in its ORSA whether it meets its capital requirements with and without it (Art 45(2a)). The interest rate charge is the worse of the up and down shocks of Delegated Regulation 2015/35, Arts 166–167. The 2025 review, applying from 30 January 2027 (Directive (EU) 2025/2 and Delegated Regulation (EU) 2026/269), recalibrates the interest rate shocks so that they also apply when rates are negative, limited by a floor that rises with maturity. The detail is in M4.6: Solvency II and insurance regulation; banks' rate risk rules are in M4.5: Liquidity and IRRBB regulation.
Spark Atoms
Spark AtomWhen hedging becomes a liquidity problem: UK pensions, 2022
Spark AtomMatching PV01 raised the charge
Key takeaways
- Insurer ALM starts from long, fairly predictable liabilities: RiskAtoms' run to 2069, its bonds to 2045, leaving €3,739m of payments to reinvestment.
- Effective duration and PV01 by book: annuities 9.2 years, savings 3.3, term −1.5, non-life 2.3; overall 5.03 against 5.48, a gap of −0.13.
- ΔOF ≈ −(D_A A − D_L L)Δ + ½(C_A A − C_L L)Δ²: with the gap closed, more convex liabilities (annuities and sold guarantees) make own funds fall both ways, −€447m at −100bp and −€158m at +100bp.
- The Solvency II shocks are relative and not parallel; on this curve the up shock binds with €393m, and matching PV01 does not minimise it.
- A run-off shrinking by q a year is a geometric series: PV = C₁v/(1 − qv), D = 1/(1 − qv). Good for short-tail claims, poor for annuities.
- The matching adjustment discounts matched, ring-fenced annuities at risk-free plus spread less fundamental spread: 75bp would add €1,304m to own funds here.
Reaction
Check what stuck
Question 1 · objective 2
An insurer holds €60bn of bonds with a duration of 7 years against €55bn of liabilities with a duration of 9 years. What is its duration gap D_A − (L/A)·D_L, in years?
Question 2 · objective 2
RiskAtoms' bonds lose €27.19m per basis point rise; its best estimates lose €27.88m. To first order, what do own funds gain or lose if rates fall 10bp, in €m (negative for a loss)?
Question 3 · objective 3
RiskAtoms' own funds fall €447m if rates fall 100bp and €158m if they rise 100bp. What explains a loss both ways?
Question 4 · objective 4
A run-off pays 1,000 in year 1 and then 40% less each year (q = 0.6), forever. At a flat 3%, what is its Macaulay duration, 1/(1 − qv), in years?
Question 5 · objective 5
Annuity-backing bonds earn a spread of 1.20% over risk-free; the fundamental spread for their default and downgrade risk is 0.45%. What matching adjustment is added to the discount rate, in basis points?
Glossary
- Asset-liability management (ALM)
- Asset-liability management: choosing and managing assets so that they meet the liabilities as they fall due, and so that the balance sheet holds its value when markets move.
- Cash-flow matching
- Cash-flow matching: buying assets whose payments arrive when, and in the amounts that, the liabilities fall due.
- Reinvestment risk
- The risk that liability payments due after the assets mature must be met from money reinvested at rates nobody knows today.
- PV01
- The change in value for a one basis point rise in rates. Here measured on the whole curve, as value lost.
- Effective duration
- Duration measured by revaluing on the curve moved up and down a little: the percentage change in value per unit change in rates. It works for cash flows that themselves depend on rates.
- Duration gap
- Duration gap: D_A − (L/A)·D_L. Zero means own funds do not change, to first order, when rates move in parallel.
- Convexity
- The curvature of value in the rate: how much the duration itself changes as rates move.
- Guaranteed crediting rate
- A minimum crediting rate promised to savers. When rates fall below it, the insurer pays the difference: an option it has sold.
- Matching adjustment
- Matching adjustment: an addition to the risk-free rate used to discount predictable liabilities backed by a ring-fenced portfolio of matching assets, equal to the assets' spread less a fundamental spread for default and downgrade.
- Fundamental spread
- Fundamental spread: the part of a bond's spread that pays for expected default and downgrade losses. It stays with the insurer and is not part of the matching adjustment.
- Liability-driven investment (LDI)
- Liability-driven investment: a pension scheme strategy that hedges the rate sensitivity of the liabilities, often with leverage through swaps and repos that need collateral.
Deep Dives & Origins
Public dataReal events cited on this page
Deep Dives
- P. Alexander, R. Fakhoury, T. Horn, W. Panjwani and M. Roberts-Sklar, “Financial stability buy/sell tools: a gilt market case study”, Bank of England Quarterly Bulletin, 2023. Intermediate.
- Directive 2009/138/EC (Solvency II), Arts 77b and 77c on the matching adjustment, legislation.gov.uk copy. Advanced.
Origins
- European Parliament and Council, Directive 2009/138/EC, Art 77b (version at 31 January 2020) and Art 77c, legislation.gov.uk.
- European Parliament and Council, Directive 2009/138/EC, Art 45 (own risk and solvency assessment, including paragraph 2a), legislation.gov.uk.
- European Commission, Delegated Regulation (EU) 2015/35, Art 166 (EIOPA Single Rulebook) and Art 167 (legislation.gov.uk, as adopted).
- European Commission, Delegated Regulation (EU) 2026/269, recitals 23–24, EUR-Lex, 2026.
- Alexander, Fakhoury, Horn, Panjwani and Roberts-Sklar, “Financial stability buy/sell tools: a gilt market case study”, Bank of England Quarterly Bulletin, 20 November 2023.
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