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Drivers of Downward-Sloping Swap Spread Curves

Article Quant Q&A · Author: basisnerd123

Summary

The document discusses why swap spreads can decline with tenor, especially at the long end, and emphasizes that the drivers vary by market and maturity segment. In developed markets, pension funds and other asset-liability investors may receive long-dated fixed swaps to add duration against long-duration liabilities. That demand can put downward pressure on long-end swap rates and spreads. The responses also describe technical flow effects where limited long-dated government bond supply leaves swaps as a practical way to obtain duration.

Other explanations include Treasury supply and maturity-extension concerns in the United States, changing perceptions of government and swap counterparty credit risk, and central-bank expectations or risk-off flows in emerging markets. The discussion is qualitative and draws on market examples rather than a single causal model. It cautions indirectly that observed curve shape may reflect different short-, medium-, and long-end forces, so no one explanation applies universally.

Key ideas

  • Long-duration investors may receive fixed in swaps to hedge liabilities, pressuring long-end swap rates.
  • Limited issuance of long-dated government bonds can channel duration demand into swaps.
  • US Treasury supply concerns can affect long-end swap spreads and relative bond performance.
  • Credit perceptions and clearing arrangements can alter the relationship between government and swap rates.
  • Policy expectations and risk-off flows can invert swap curves in some emerging markets.
  • Different curve segments may respond to distinct drivers, so explanations depend on market context.

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Full text
# Downward Sloping Swap Spread Curve


# Downward Sloping Swap Spread Curve












After observing swap spreads in the market, I have noticed that the swap spread curve is downward sloping. Why is this? I have tried looking around the internet for answers, but have not found anything.

The only rational I could think of is that corporate issuers, who want to receive fixed on swaps to hedge their B/S interest rate exposure, have to enter in swap agreements with tenors of 5+ years (to match the maturity of their bonds), which drives the rate on the fixed leg of swaps down (and hence causes the swap spread curve to slop downwards).

Any input is appreciated.

EDIT: I am referring to US swap spreads.

## Answer by math (score 7)

https://quant.stackexchange.com/a/59745

If I look at the market I think this is mainly driven by the very nature of the long end investors of the swap curve. Compared to govi curves the swap curves provides a much better liquidity in longer tenors. Although we have seen a trend of bringing longer dated bonds to the market by government, too. Austria and Belgium are just two examples of these and Germany plans to add a new 50y benchmark bond. Now why is the swap curve downward sloping in the longer part causing the spread to be negative? On that part of the curve ALM investors are active and it is a huge market. These investors usually hedge their interest rate risk (in particular for DB plans, see also the new Dutch pension reform) using swaps. The bulk of liabilities has normally a duration of 25-35y. So effectively they are short a very long dated bond. To compensate they want to add duration to their portfolio to hedge this risk. Easiest way to do this is via receiving in the long end swap curve thus putting pressure on the long end swap curve.

## Answer by Jan Stuller (score 4)

https://quant.stackexchange.com/a/59759

This post is more related to EM markets, rather than developed markets (so could add some additional examples, to the already good DM examples given by @math above):

(i) In some countries (for example CZK prior to 2019), the Ministry of Finance preferred to issue shorter-dated bonds (up to 5 years), and there was less issuance of longer-dated bonds. As a result, pension funds and other type of funds, who wanted to go long duration, had no other choice but to receive longer-dated swaps. This caused the Swap curve to be "permanently" inverted from the 5y point up to the 10y point: it was just a "technical" flow problem.

(ii) The ECB has consistently failed to hit its inflation targets for the past decade. This has made the markets skeptical about inflation expectations in Europe (not just the Eurozone), and the markets tended to price in rate cuts for any sovereign European swap curves, where the central bank's policy diverged from the ECB policy of low rates (again, you could see this for example on the CZK curve, prior to the Covid19-driven change in CNB's policy).

(iii) During any risk-off scenario, fast money tends to receive emerging market swap rates between the 5y up to the 10y pillar (rather than receiving the short end): this can also make the curve inverted, whenever there is a flight-to-safety and at the same time the local central bank's rates are relatively high (which anchors the short-end of the curve)

## Answer by DS_London (score 2)

https://quant.stackexchange.com/a/59771

Classically credit spreads widen with maturity, as the effect of default risk increases (and hence the extra yield required by investors) more rapidly for weaker credits.

In the “good old days” government bonds were AAA and OTC swaps were close to A-rated (reflecting the credit quality of the counterparts banks). Then came the Global Financial Crisis and investors were more sceptical of government bond ratings, while at the same time G10 swaps moved almost completely to clearing houses (which greatly diversified the counterparty risk).

In the US, the risk at the long end comes from a possible sizeable supply shock and extension of the maturity profile of Treasuries, as the deficit increases. Hence long-end Treasuries have been underperforming swaps.

In Europe, as others have commented, it is the use of long-dated swaps by pension funds which drives spreads via asset-liability matching. In times of market stress, stocks take a dive so the assets of funds decrease, while at the same time rates fall so the present value of liabilities increase. Funds need to hedge this by adding duration, and the most common way is to receive fixed on 20y-30y swaps (which of course only adds to the downward pressure on long rates). Thus you see 30y German bonds massively underperform 10y as the swap curve flattens sharply (while at the same time issuers become wary of long-end supply and government term premium picks up). We saw this post-Lehmans, during the sovereign debt crisis and most recently Covid: at the start of 2020 the swap spread curve on 10-30 was effectively flat, then dived in March and is now around 75% recovered.

## Answer by user42108 (score 0)

https://quant.stackexchange.com/a/59755

If you look at models for swap spreads, the drivers for short, medium and long-end are quite different, i.e. there's a sort of implicit market segmentation hypothesis.

Re: Dimitri's comment on regs - you could look at the SDR volumes data to get an idea of whether long-end activity is declining.

EDIT: models I had in mind were for USD spreads.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.