Discounting Uncollateralized Swaps After LIBOR
Summary
The document discusses how to value uncollateralized over-the-counter derivatives after LIBOR cessation. Under the older convention, a LIBOR curve could serve as a discount curve to reflect unsecured funding, while collateralized trades were discounted using an overnight indexed swap curve. It outlines two possible transition approaches: calibrate a replacement three-month swap curve by adding spreads to SOFR, or discount all trades at SOFR and represent the lack of collateral through credit valuation adjustment or related valuation adjustments.
The discussion does not establish which approach will become standard. It notes that academics may favor the risk-free overnight rate with valuation adjustments, while practitioners may prefer a spread-adjusted swap curve for continuity and legacy contracts. It also describes the motivation for credit-sensitive or term funding benchmarks and the need for each institution to account for its own funding spread. These are competing valuation conventions and benchmark proposals, not a settled market rule; the appropriate treatment depends on market practice and the contract context.
Key ideas
- Uncollateralized LIBOR trades historically used a LIBOR based discount curve to reflect unsecured funding.
- One transition proposal is to build a spread-adjusted three-month swap curve over SOFR.
- Another proposal discounts trades at SOFR and captures uncollateralized credit risk through valuation adjustments.
- Term and credit-sensitive benchmarks aim to reflect bank funding conditions that overnight secured rates may not capture.
- The document describes unresolved alternatives rather than a settled convention.
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Full text
# Uncollateralised trades in Libor transition
# Uncollateralised trades in Libor transition
Consider an OTC derivative traded with no CSA agreement, i.e. the trade is uncollateralised. My understanding is that a Libor swap curve is used in this case to discount the cashflows for this derivative as that reflects the funding, see Fuji et al 2010. This discount curve is constructed in the usual multicurve paradigm of inputs OIS and Libor xM curves, then using say 3M Libor curve to discount the cashflows. In a collateralised trade I would use the OIS to discount instead of Libor.
What happens after Libor cessation to the discount curve, what is the fair discounting curve? A naive approach would be to use the fallback curve bootstrapped from OIS swaps + ISDA fallback spread, but this doesn't seem natural to me.
## Answer by Ami44 (score 5, accepted)
https://quant.stackexchange.com/a/63029
Two replacements for the 3M Libor curve are possible:
- Construct a new 3M Swap discounting curve by adding spreads on top of the SOFR curve. These spreads can be calibrated on uncollateralized 3M SOFR swaps.
- Discount all derivatives, regardless if collateralized or not, with the SOFR curve, which is the true risk free curve. The credit risk arising from not being collateralized will then be accounted for by the CVA or maybe other xVAs.
It is yet unclear (to me) which alternative will be more popular. The second is liked more by academics while practitioners might like to see something like a 3M swap curve. Having a 3M Swap curve might also ease the transition and make it easier to deal with legacy contracts
## Answer by ir7 (score 4)
https://quant.stackexchange.com/a/63036
To add to above answer, this GARP article is summarizing recent work on new benchmark indices that attempt to address what Libor was meant to ('fairly') cover, but RFR’s don't, namely (term, unsecured) funding and some credit sensitivity: Ameribor, AXI, US Dollar ICE Bank Yield Index etc.. One banker points out there that an index like SOFR “would plummet when our costs of funds go up” (SOFR, as a secured rate derived from overnight repo transactions, may tighten in volatile times, when market participants look for safety).
One complementary aspect is that an institution has to add its own funding spread to the ('fair', market average) funding rate (whatever that is). So far an institution would add that spread to LIBOR rate, now the institution (corporate treasury) would need to make up new spreads and add them to the OIS/RFR rate.
Finally, this down-to-earth BIS article explains why seeking benchmarks for funding may still be quite relevant, using the historical ‘switch’ in the late 1980s as example, when market participants moved away from using benchmarks based on US Treasury bill rates (the prototypical 'risk-free rate') to those based on eurodollar rates. The primary driver of this "benchmark tipping" (as the authors call it, if I understood correctly) was that, in seeking to manage asset-liability mismatches, banks found eurodollar rates a much closer approximation to their actual borrowing costs and lending rates than US T-bill rates.
UPDATE: Bloomberg made its move too with BSBY.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.