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Using FX Forwards and Cross-Currency Basis to Derive EUR Funding Yields

Article Quant Q&A · Author: Oamriotn

Summary

The document explains how to translate a USD Libor curve into an equivalent EUR funding curve. Its central method is to convert EUR into USD at spot, accrue the USD cash at the relevant Libor rate, and convert it back to EUR at a forward FX rate. Comparing spot and forward rates with the USD discount factors gives the implied EUR discount factors, with care needed to match the currency pair’s quote convention.

FX forwards are observable for shorter maturities, while cross-currency basis swaps can imply forward FX rates at longer maturities because their value depends on those rates. Basis swaps often extend further along the curve than outright forwards. The document says either market can be used, with the choice guided by relative liquidity across maturities and currency pairs. For EUR/USD, it reports that basis swap quotes alone are commonly considered sufficient to calibrate the forward curve for cross-currency funding costs. This is a funding-cost construction, and the answer notes that the meaning of “equivalent yield” depends on the intended application.

Key ideas

  • Translate USD funding into EUR by combining USD discount factors with spot and forward FX rates.
  • The FX quote direction must be handled consistently when deriving discount factors.
  • Cross-currency basis swaps can imply forward FX rates where outright forwards are not readily observable.
  • Choose forward and basis market inputs according to their liquidity across the relevant maturities.

Tags

Full text
# Convert USD yield into EUR yields


# Convert USD yield into EUR yields












I want to calculate the EUR equivalent yield from the USD yield curve. For example : how to translate the USD libor curve into an EUR equivalent yield curve ?

Do I need to use FX forwards or is the X-CCY basis enough ?

## Answer by atkins (score 2)

https://quant.stackexchange.com/a/30046

I'm not sure exactly what you mean by the "EUR equivalent yield", but I think that what you are asking is "How do I calculate the effective cost of funding EUR cashflows at USD Libor?".

If that's the case then, fundamentally, what you need are FX forward rates. For a given forward date you can imagine funding EUR at USD Libor by switching some amount of EUR into USD at the spot FX rate, accruing it at USD Libor, and then switching it back into EUR at the forward date using the forward FX rate. You then find something like

$$ P^\mathrm{EUR}_\mathrm{USD\ Libor\ 3m}(T) = P^\mathrm{USD}_\mathrm{USD\ Libor\ 3m}(T) \frac{fx(T)}{fx(0)}$$

which defines the discount factors of your "equivalent curve" in terms of those of the native USD Libor 3m curve (take care to get the FX in the correct direction, depending on the convention for the relevant pair).

The question then is, whence do you source FX forward rates? Well, there is of course an observable FX forward market, but they are typically only observable for the relatively short term. What about longer terms? This is where the cross-currency basis spreads come in: the value of a cross-currency basis swap depends on forward FX rates, so it follows that observed cross-currency basis spreads can be used to imply forward FX rates. Cross-currency basis swaps are typically quoted to much longer maturities than are seen in the FX forward market (as far out as 50Y+ in major currencies), and so these tend to be the best source of information on long-term FX forward expectations.

Ultimately then, the answer to your question is that you can use either or both FX forward rates and cross-currency basis spreads, since they both serve as a source for FX foward rates. Which you should prefer will depend on the relative liquidity of the respective products at each point in the term structure, and this depends on the particular currency pair you're dealing with. For EUR and USD, however, in my experience, the cross-currency basis swap market alone is deemed to allow the full FX forward term structure to be calibrated sufficiently well for the purpose of determining cross-currency funding costs.

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.