Managing and Hedging IRRBB

Paul Newson

The previous chapter discussed how IRRBB is usually identified and measured; this chapter will now provide a description of how it is controlled and managed by banks. The prime focus is on those open mismatch positions that are essentially discretionary – ie, fairly easily closed – and how a bank might best organise itself to reduce such unnecessary risk in a way that is also efficient and cost-effective. In this, the general presumption is that the bank has no appetite for expressing a particular interest rate “view” in its banking book or, in other words, that it will want a gap report that generally shows a minimum of mismatch risk.


As mentioned in Chapter 2, interest rate derivates, particularly IRSs, in theory provide a ready means of hedging any simple interest rate risk that arises from the origination of customer products, particularly fixed rate loan products where cash funding is unlikely to be available at the same re-pricing maturity as the customer product.

For example, a three-year fixed rate mortgage initially cash-funded at three-month Libor creates an exposure to the funding rate rising. A three-year pay fixed/receive Libor closes the risk since, if rates rise, the increased cost of the funding is offset by the gain on the swap while, if rates fall, the loss on the swap is offset by the benefit of the cheaper funding. The relevant cashflows are:

    • receive: three-year Libor plus margin from the customer; three-month Libor from the swap; and
    • pay: three-year Libor on the swap; three-month Libor on the funding.

    All the Libor legs net out, so the bank simply locks in the margin – assuming, of course, that the mortgage stays on the bank’s books for the contractual length of the hedge.

    Other than for very long maturities, the interest rate swap market is normally “deep and liquid”, meaning that there are sufficient market makers (primarily investment banks and the trading arms of larger commercial banks) and end-users (retail and commercial banks, pension funds, investment managers and corporates) to ensure that any “standard” product is more or less immediately available at a consistent price across the market, and that the bid–offer spread (the difference between what the market maker will quote to someone wanting to receive fixed and someone wanting to pay fixed) will be tight.

    In addition to simple vanilla fixed/floating swaps, the two other commonly found varieties of an interest rate swap in a banking book are the following.

    • Amortising swaps: These are instruments whereby the notional principal decreases over the life of the swap, and which are useful when hedging, for example, a mortgage or other fixed rate loans where customers are expected to repay the principal gradually over the life of the loan rather than at the end.
    • Basis swaps: These are floating/floating swaps where one party pays a variable rate based on one index (eg, Libor) and the other party pays a variable rate based on another index (eg, BBR). These are useful to hedge, for example, BBR-based mortgages funded at Libor (see Chapter 6 for a fuller discussion of basis risk).

In addition, banks may purchase interest rate options, known as “caps” and “floors”, which give the buyer the right, but not the obligation, to borrow or lend (notionally) at a given rate for a specified period in the future. These are often used to hedge “capped” mortgages or “floored” deposit products where the rate is guaranteed not to rise above (or fall below) a given level.

The final type of derivative that might be used as a hedge is a “swaption”, which is an option to enter into an IRS at some point in the future. These are potentially useful where the final sales volume of a fixed rate product is unknown, or where customers might pre-pay/withdraw at a date different than that which the simple hedging has assumed – although, as will be explained later, the appropriateness of such instruments to hedge customer behaviour is debatable.


It might seem, therefore, that interest rate risk management simply involves hedging all fixed rate and base rate linked products, one for one, with derivatives as they are originated, and that therefore interest rate risk in the banking book should always be near zero. Some banks, particularly smaller ones, do broadly adopt this approach, and their treasuries will decide both what needs to be hedged and also execute the necessary trades with the external market. However, there are a number of problems with this simple approach.

First, generally speaking it is impractical to hedge separately each individual customer drawdown – more typically, the overall positions will be reviewed on, say, a weekly, basis. In practice, most new fixed rate products will also be pre-hedged by forward-starting swaps based on estimated sales and, in the case of fixed rate mortgages, the customer usually has up to six months to decide whether or not to draw down. This means that the control function will mainly be involved in adjusting the original forward hedges to the actual level of sales achieved (rather than transacting entirely new hedges for products already sold and drawn down). Additionally, hedges of existing fixed rate products will have to be reviewed periodically to take account of customers who have repaid more of their loans, or who have withdrawn more from savings products than was originally expected when the items were hedged originally. Thus, in a bank of any size there will always be some small degree of interest rate mismatch due to “operational lags” – a more efficient and timely process might reduce this, but its cost would probably easily exceed any benefit.

Risk can also arise since it is not always optimal, even on a bulk basis, to hedge every product with a derivative on a one-for-one basis. If the bank needs to both pay fixed swaps (to hedge fixed rate lending) and receive fixed swaps (to hedge fixed rate savings), then it would pay the bid–offer spread and other dealing costs on both transactions. It would be more sensible to let one product hedge the other and only transact one IRS in respect of the difference. Furthermore, the situation becomes more complicated when anticipated customer flows are brought into the equation. If, for instance, the bank has an unhedged fixed mortgage position but anticipates a flow of fixed rate savings in the near future, then it might be sensible to leave the mortgages unhedged for a short period – but of course this involves a degree of judgement as the savings flow might not all materialise and rates might move against the bank.

There are other costs in addition to the bid–offer spread involved in maintaining a derivative portfolio. The deals need to be confirmed and documented, and processes and IT systems need to be built. All this involves cost, and so it might not be deemed worthwhile to correct a small amount of mismatch. Also, derivatives with wholesale counterparties (or transacted via exchanges) need to be supported by collateral as, in the event of the bank defaulting, the counterparty would otherwise rank as an unsecured creditor in respect of any positive value that the swap might have at the point of default. Collaterising the swap means simply that the bank has to lodge cash or high-quality bonds with the counterparty (or exchange) equal to the current value (to the counterparty) of the swap plus, often, an amount of initial margin; such collateral has to be funded, and the bank also needs to have the ability to value its swaps daily to re-compute the necessary level of collateral and agree this with the counterparty – all of which involves further cost.

For these reasons, banks generally try to limit the size of their derivative portfolio; however, in doing so, they must be prepared to accept some degree of risk. The typical method of reducing the use of external derivatives is to use internal swaps, or sometimes internal loans and deposits, to transfer risk from the individual businesses (mortgages, savings, credit cards, etc) to the treasury function, and for the latter to hedge externally the net position as it judges appropriate.

Of course, the treasury function will also be responsible for funding the bank as a whole – ie, borrowing or investing any net difference between total borrowing and total lending – and managing its liquidity by means of purchasing sufficient liquid assets and making sure it has adequate and diverse sources of funding in case of stress. In small banks and building societies, this treasury function also tends to be the dealing function that then transacts the necessary external deals and hedges with the external market. Such departments, although they deal with the market, are not really “trading” as they are only “price takers” – from the perspective of the wholesale counterparty, they are simply a corporate client. Internally, such small treasuries are much more risk/ALM management functions than they are trading functions.

Larger banks, in addition to banking book businesses, often have trading books – both to support their corporate clients and, subject to board approval, to take active proprietary positions. This makes the roles of the treasury function more challenging from a governance perspective. On the one hand, it clearly makes sense that all external market transactions are routed through one dealing function. On the other hand, however, a professional dealing function, with its own profit targets, is arguably not ideally suited to make risk management decisions on behalf of the banking book businesses since product hedging is not necessarily their area of expertise, and their prime focus is on trading profit rather than minimising the interest rate cost for the wider bank. Also, the internal incentive structure may give rise to conflicts of interest between the trading function and the treasury function.

For these reasons, larger banks typically establish a corporate treasury function entirely separate from the dealing function to undertake the roles of:

    • determining the overall funding requirement and how this should be met;
    • ensuring there is an adequate supply of liquid assets;
    • netting individual businesses’ risk positions; and
    • deciding on what external hedges are necessary.

The corporate treasury will then execute internal deals with the dealing function to close any overall net positions it has taken from the individual businesses, leaving the dealing function with the sole responsibility of closing this position with the external market at the best obtainable price – ie, in exactly the same way any client position would be taken and then closed. The dealing function in this model would have no input into the risk management of the banking book. Indeed, some corporate treasuries go one step further and deal directly with the market themselves, which ironically could be viewed as bringing them back full circle to a small bank model.


Funds transfer pricing (FTP) is the mechanism by which banks establish the internal price (or transfer rate) at which a customer-facing business – such as mortgages or savings – pays for (or receives on) the funding it receives from (or provides to) the treasury function. FTP will usually have a number of components, such as a pure interest rate cost, a liquidity cost and sometimes a capital cost. Its overall purpose is to ensure that the full costs of providing a product are reflected properly in the final external price quoted to the customer.

Whereas in previous chapters the reader might have imagined that the product is originated and the resultant risk is then hedged, for fixed rate products it should be borne in mind that the process more usually occurs in reverse. For example, the price of a three-year fixed rate mortgage would be the sum of the expected three-year swap rate at the time of drawdown (usually locked in by means of a forward-starting swap), plus the liquidity cost, plus any capital cost, plus the appropriate credit spread, plus the bank’s target margin. FTP therefore tells the business what the first three elements are, thus allowing it to focus on pricing for credit risk, marketing and net profitability – ie, those elements that are under its control.

With regard to the interest rate component of FTP, the objective is to ensure that funds provided to (or from) an individual business, at the required re-pricing maturity, carry an interest rate that reflects most accurately the actual cost (or benefit) to the bank as a whole of raising (or investing) the funding that the business requires (or generates). It might be thought that simply using the current market rate that the bank would pay in the external market would achieve the desired result, and indeed some banks do opt for this approach. However, this could have unintended consequences.

Consider a bank that had roughly equal volumes of loans and deposits of similar maturity. If the two businesses had to trade with the internal treasury, for funding and any swaps necessary to close interest rate risk, paying the same bid–offer spread that the treasury would charge external clients, the net result would be that the treasury would “make money” to the detriment of the business; however, in practice it would have done nothing more than net off the offsetting positions. In such circumstances, the bank may well decide that internal transactions should be priced at “mid”, which is another common approach used. Alternatively, it might decide to continue to utilise genuine two-way market prices, but in some way allocate the treasury “profit” back to the businesses.

Using mid-market prices, or allocating treasury profit back to businesses, is generally more workable in cases where the internal treasury is not regarded as a profit centre. However, it becomes more difficult where the bank has a full trading book whose dealers are primarily incentivised by bonuses that, in turn, are based on their trading performance. In these circumstances, particularly where supporting the banking business does require some market dealing, the dealers would feel understandably that they were effectively subsidising the internal clients to the detriment of their own profit and loss.

Another variant found in FTP practice is the use of a backward-looking average rolling rate as opposed to the spot funding rate that the bank, externally, would pay or receive. For example, the bank might set the internal funding “benchmark” as the average of three-month Libor as measured over the preceding 60 days. Cash funding would thus be provided at this rate and, where required, internal swaps’ variable legs would also use this rate. The rationale behind such an approach would be that cash funding involves a relatively small number of large funding deals on one side of the balance sheet and a large number of small customer deals on the other side. Assuming the interest rate re-pricing dates of all the customer deals are reasonably evenly distributed, the banking business would be at risk of a sudden spike in rates on the day one of the funding deals rolled. This is known as “re-set risk”. Using an average rate largely removes this risk from the banking business (as an average rate will be considerably less prone to daily spikes) and moves it to the treasury, who should be better placed to arrange external funding in such a way as to minimise it. Also, banking businesses would be less tempted to try to play the market themselves by, for example, delaying hedging in the expectation of a favourable move in rates, and would have a far higher degree of certainty around their cost of funding allowing them to price their products more effectively.

This book does not set out here to recommend any one particular approach, but merely to highlight that practice does differ. There is probably no solution that is entirely ideal, and certainly no one model that can be applied to all banks. A few attributes of a good FTP system may, however, be suggested. For one, it should be relatively simple and transparent; from an overall bank perspective, FTP is a zero sum game and its discussion should not consume an undue portion of management time. An overly complex system will waste time and potentially encourage “gaming” as each function tries to maximise its own reported performance, but in practice only to the detriment of other functions.

While internal deals are clearly a good, transparent way of effecting FTP and minimising unnecessary external transactions, they themselves are not entirely free of overhead in terms of processing and reconciliation. Even demonstrating that, on consolidation, they all net out to zero can pose a considerable challenge, particularly if the bank’s corporate structure changes or it subsequently changes its FTP model. The FTP system should be designed so that the various functions involved are incentivised to focus on what they are best suited to do: the customer-facing businesses on credit, marketing and pricing, the corporate treasury on managing the interest rate risk, and the dealing function on funding and hedging at the best achievable market prices.

No single FTP model can of itself entirely eliminate inappropriate behaviour – it must always be supplemented through appropriate governance and independent oversight. For example, much hedging is based on the assumed behavioural maturity of the product, and management needs to be aware that the businesses’ own estimates might, in a poorly run bank, be driven by a desire to lower their funding cost regardless of the risk this might obscure. Even ensuring that the business always bears the cost of its behavioural assumptions being wrong is not necessarily a sufficient mitigant as, if by the same token, the business is allowed to benefit from a favourable move in rates, then this could possibly incentivise the taking of a rate view by deliberately manipulating assumptions. Overall, the FTP approach selected will be a function of the size and complexity of the bank, the manner in which functions are incentivised and the strength of senior management.


All hedging discussed so far has covered the hedging of individual products – for example, a particular fixed mortgage offering or fixed savings offering. Typically, this will involve the business entering into an internal swap for the total product volume and then the treasury function closing any net position with the external market. This is termed “micro hedging”.

Such hedging, however, does not necessarily remove all interest rate risk from the banking book. There will remain potential risks stemming from the overall structure of the balance sheet and the nature of the products the bank offers. A classic example of this is what is known as “margin compression”. This is where the general level of interest rates falls so low that further re-pricing down of variable rate assets can no longer be matched by re-pricing down the corresponding liabilities as the rate on the latter has hit zero – margin is therefore squeezed.

A possible solution would be for the bank to buy a series of IROs that would pay out should interest rates fall below a certain level. If rates did fall, the gain on the option would help offset the margin compression loss – but if interest rates rose, then the bank would only lose the premium it paid on the option. Alternatively, the bank might opt to enter into some receive fixed/pay floating swaps and pay no premium – again, if the rates fell the bank would gain on the swaps as it would be paying less, but this time it would lose if rates rose, so arguably this might not be considered a “good” hedge. However, if the bank could demonstrate to itself (and possibly to its regulator) that if rates rose it would be able to gain by “re-margining”, then such a strategy could be regarded as a “macro hedge”.

Another example of macro hedging is the hedging of non-dated liabilities; this is covered in more detail in Chapter 8, but essentially it is again hedging the structure of the balance sheet to keep the margin stable.

There is often a thin dividing line between a macro hedge designed to protect the bank from a perceived vulnerability and simply entering into derivative position based on nothing more than a “view” about short-term interest rate movements. For a particular strategy to constitute a genuine macro hedge, it is suggested that it should meet the following criteria.

    • Its purpose should be clearly documented and approved at a sufficiently senior level in the bank.
    • While some view on the general direction of interest rates in the medium term will often legitimately have its part to play in the decision to proceed, this should not be a “trading” decision designed to exploit a view on potential short-term moves.
    • The positions should ideally be held in a separate book, and their performance should be monitored regularly and reported to the authorising committee.
    • While some degree of “active” management may be necessary to ensure the hedge is still effective and that trades are executed at the best price, frequent chopping and changing in response to daily interest rate changes, particularly without explicit authority, could make the positions appear no different than proprietary trading positions that should more properly be held in the bank’s trading book.
    • The authorising committee should be aware that macro hedges are often inherently predicated on certain assumptions, such as an ability to re-margin in a rising rate environment or the ability to retain low interest bearing deposits. The performance of the macro hedge should be supplemented with an analysis of the impact of such assumptions breaking down.

Panel 5.1 provides an example of what might appear to be a prudent macro hedge but which, on closer examination, might arguably seem to be more of a proprietary position.


While a derivative such as an IRS – if assumptions about when the hedged item re-prices are correct – can be shown to remove the economic risk of any actual loss from a subsequent change in interest rates, the accounting treatment of derivatives can cause problems. The basic rule under IAS 39/IFRS 9 is that a derivative must always – even if held in the banking book – be accounted for on an MTM or fair value basis, whereas in a banking book the item being hedged will be accounted for on an accruals basis.


Consider a bank with a steady business line in fixed rate mortgages. Assume that interest rates are currently at a very low level and that the general belief is that, at some point, they will rise. The proposal is therefore to raise a significant volume of fixed rate funding by executing a series of pay fixed swaps at the current low level of interest rates to fund future fixed rate mortgages when, it is believed, rates will be higher.

Intuitively, this seems to make sense – take advantage now of low rates to fund future mortgages more cheaply and thus lock in a higher margin. However, the whole strategy is really based solely on a rate view, as it only makes money if rates do rise more quickly than implied by the current yield curve and, if rates fell, it would lose money. The mortgages are actually irrelevant to the strategy as their price, although it will be fixed, has not yet been fixed, so there is no risk to hedge. It all comes down to a belief that money can be made since the bank thinks rates will rise more quickly than implied by the current yield curve.

A second bank, without a fixed rate mortgage offering, could achieve exactly the same economic result by also entering into an equivalent volume of pay fixed swaps, but internally that would look just like a proprietary position, which may be less acceptable to senior management.

Consider a five-year fixed rate loan funded at three-month Libor, hedged by an IRS whereby the bank pays five-year Libor and receives three-month Libor. The Libor interest flows net out and the bank receives its margin, fixed each year.

Initially, the swap has no value, so no accounting issue arises – however, assuming interest rates then rise, the swap will have a positive value on an NPV basis. Of course, in practice the gain on the swap, when it is realised in cash form, will be offset exactly by the losses on the underlying loan and deposit, but MTM accounting will require the “profit” on the derivative to be taken to P&L immediately, whereas the “loss” on the loan and deposit will only be recognised when it actually arises. The impact on reported net profit will be a profit in early years and losses in later years. Over the five-year period, these will on a cumulative basis net out, but it introduces volatility into reported profit that does not reflect any underlying economic reality – and this in turn can have a negative impact on market and investor perceptions of the bank’s performance. This effect is illustrated in Panel 5.2.


A bank lends £50,000 for five years fixed. Rates are currently 5% for all tenors, so the price of the loan (ignoring margin) is also 5%. The funding is only for one year fixed, so to hedge the risk the bank transacts a pay fixed/receive floating IRS at 5%, the floating leg of which (for simplicity) re-prices every year. After one year – just before the funding and the swap re-price – interest rates all rise by 1% to 6%, and stay at this level for the remainder of the period.

To compute the reported P&L of these transactions, it is necessary to consider first how the MTM, or “fair value”, of the swap will change over the period.

MTM is always the NPV of all those future cashflows that are fixed at the time of the calculation – including, for a swap, the notional principals.

The initial MTM of the swap is:

Remaining years Pay Receive Net NPV @ 5%
1 (2,500) 52,500 50,000 47,619
2 (2,500)   (2,500) (2,268)
3 (2,500)   (2,500) (2,160)
4 (2,500)   (2,500) (2,057)
5 (52,500)   (52,500) (41,134)
Total       0

As would be expected, this is zero. This calculation is now repeated showing the MTM as at the end of years 1–5. Note that rates have now risen to 6% and the interest on the floating swap leg is now £3,000.

End year 1:

Remaining years Pay Receive Net NPV @ 6%
1 (2,500) 53,000 50,500 47,642
2 (2,500)   (2,500) –2,225
3 (2,500)   (2,500) –2,099
4 (52,500)   (52,500) –41,585
Total       1,733

End year 2:

Remaining years Pay Receive Net NPV @ 6%
1 (2,500) 53,000 50,500 47,642
2 (2,500)   (2,500) (2,225)
3 (52,500)   (52,500) (44,080)
Total       1,337

End year 3:

Remaining years Pay Receive Net NPV @ 6%
1 (2,500) 53,000 50,500 47,642
2 (52,500)   (52,500) (46,725)
Total       917

End year 4:

Remaining years Pay Receive Net NPV @ 6%
1 (52,500) 53,000 500 472
Total       472

End year 5:

The swap has now matured and so has zero MTM. The final profit and loss for all five years is therefore:

  Year 1 Year 2 Year 3 Year 4 Year 5 Total
Interest received on loan 2,500 2,500 2,500 2,500 2,500 12,500
Interest paid on funding (2,500) (3,000) (3,000) (3,000) (3,000) (14,500)
Interest paid on swap (2,500) (2,500) (2,500) (2,500) (2,500) (12,500)
Interest received on swap 2,500 3,000 3,000 3,000 3,000 14,500
Change in MTM of swap 1,733 (396) (420) (445) (472) 0
Total reported P&L 1,733 (396) (420) (445) (472) 0

As can be seen from Panel 5.2, the reported annual P&L is volatile only due to the need to include changes to the fair value of the derivative each year, although everything nets out exactly over the whole period.

The overall net zero impact of all the fair value changes can also be deduced intuitively as any derivative will have an initial zero value at inception and a zero value when it finally matures – what is left is what gain or loss has been realised and, when it is a true hedge, this will net off with the realised gain or loss on the hedged item. IAS 39 offers two methods of “hedge accounting that can somewhat help to remove this consequence of the basic accounting rule.

Fair value hedging

Fair value hedging essentially involves continuing to fair value the hedging derivative, but also allows fair valuing of the hedged item, meaning that there should be no net impact on reported P&L in any year if the change in the fair value of the hedge is offset by the change in the fair value of the hedged item. In example 2, the fixed rate loan as well as the derivative would be fair valued (note that when fair valuing the hedged item, account needs to be taken of only the change in value associated with the risk being hedged, meaning that any margin can be ignored).

Cashflow hedging

Cashflow hedging tackles the same problem but in a different way. The derivative is still fair valued, but changes to its value are not passed to P&L but to another reserve, termed “other comprehensive income”, and will eventually reverse out by the end of the life of the derivative.

Hedge effectiveness

For each approach, what is termed “hedge effectiveness” needs to be demonstrated. In the case of fair value hedging, this involves identifying actual products or product groups to be hedged, and establishing and documenting at the outset that the hedge will be “highly effective” in offsetting fair value changes in the hedged items. For a cashflow hedge, it needs to be demonstrated that the bank is overall subject to variability of income due to interest rate changes, and that the derivative will again be “highly effective” in offsetting this.

There is also a continuing requirement to prove, retrospectively, that the hedge has been between 80% and 125% effective (ie, not under- or over-hedged outside of this window), and any hedge whose performance falls outside of the range will no longer be permitted and the whole of the fair value change from inception will go to P&L with no offset from the hedged item.

Cashflow hedging, in that it allows consideration of the bank’s overall vulnerability to interest rate changes, is probably less onerous to demonstrate than fair value hedging, which involves a specific association of a particular hedge with a particular hedged item. The latter works reasonably well for “big ticket” items, but can become difficult where there are many offsetting products that are hedged only on a net basis. On the other hand, cashflow hedging, while it reduces P&L volatility, does impact another published measure, known as “tangible net assets”, the volatility of which can also cause an adverse impression on analysts and investors.

Finally, it should be noted that IAS 39 is due to be superseded by IRFS 9 in 2018. The new standard is more principle-based and less rules-based; in particular, the 80–125% rule will be dropped, but otherwise with respect to interest rate derivatives will be broadly similar.

Hedge accounting is a complex subject and, for a full understanding, reference should be made to a suitable textbook or the accounting standards themselves. However, the key point here is that the accounting requirements constitute a further reason why banks should only resort to using derivatives when other solutions have been exhausted, as their use involves considerable overhead and can distort published performance metrics.


Derivatives, particularly IRSs for which markets are deep and liquid, provide a ready means for a bank to hedge its open interest rate exposure. They should, however, be used sparingly, and the bank as a whole should generally only look to hedge externally any net position. This is because derivatives give rise to a number of control issues and incur costs.

Most banks will establish a central treasury function to transact internal derivatives with individual business units, and then if necessary hedge the net exposure with the external market. Sometimes, the central treasury function itself transacts directly with the wholesale market; in larger banks, the central treasury function will typically channel transactions via the bank’s separate trading/dealing function to which it is, in this regard, simply an internal client.

FTP describes the bank’s approach to determining the internal price at which the central treasury will charge individual business for funds and internal hedging derivatives. A number of approaches are found in practice, but all seek to establish an appropriate internal transfer price that incorporates the interest rate cost, the liquidity cost and sometimes the capital cost of originating and holding banking products.

While individual products will, where appropriate, be hedged individually, the bank may also on occasions enter into macro hedges designed to protect it from more structural interest rate risk. Good governance is essential to ensure that macro hedges are not simply short-term position-taking.

Accounting rules require all derivatives to be accounted for on a fair value basis, but this will create P&L volatility if the item being hedged is accounted for on an accrual basis. However, the rules do allow for this to be overcome if a hedge relationship can be established, but the process can be onerous and provides another good reason why derivatives should be used sparingly in the management of IRRBB.

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