Currency Carry with Futures





Kerry Back

Exchange rates

  • It is simplest to quote foreign currency prices in the domestic currency (dollars).
  • Cost of a euro, cost of a peso, etc. is the same concept as the cost of a loaf of bread.
  • A currency appreciates (relative to the dollar) when its cost rises and depreciates when its cost falls.

Currency carry trade

  • The currency carry trade is to borrow in a low interest-rate currency (e.g., euro) and invest in a high interest-rate currency (e.g., peso).
  • You earn the interest differential. Interest is called carry.
  • The risk is that the high interest-rate currency may depreciate relative to the other.
  • Empirically, this has been a profitable trade on average.

  • Borrowing in euros, exchanging to pesos, and depositing pesos is shorting euros and going long pesos.
  • Example: short (borrow) $100,000 of euros and go long $100,000 of pesos. Pay euro interest rate and receive peso interest rate. Earn the difference.
  • But when we sell the pesos and cover the euro loan, prices may have moved.

Currency carry with futures

  • Short euros and invest in $ = synthetic short euro future
  • Borrow $ and buy pesos = synthetic long peso future
  • Combining them equals currency carry trade ($ cancel)
  • Combining actual long peso future and actual short euro future also equals currency carry trade

Backwardation and contango

  • Futures price = spot price + cost of carry - convenience yield
  • = spot price + domestic interest - foreign interest
  • Low foreign interest \(\Rightarrow\) contango (euros)
  • High foreign interest \(\Rightarrow\) backwardation (peso)
  • So, currency carry trade = sell contango futures and buy backwardation futures

Expensive and cheap futures

  • Sell contango futures = sell futures when futures price is high (relative to spot)
  • Buy backwardation futures = buy futures when futures price is low (relative to spot)
  • So, currency carry trade = sell expensive futures and buy cheap futures (relative to spot)

Appreciation and returns

  • Consider selling 2-month euro (contango) futures and buying 2-month peso (backwardation) futures at date \(t\) and holding for 2 months, until futures price = spot
  • On peso, make

\[\text{peso-spot}_{t+2} - \text{peso-spot}_t\] \[+ \text{peso-spot}_{t} - \text{peso-futures}_t\]

  • This is spot appreciation - forward curve slope

Failure of expectations hypothesis

  • On euro, make opposite. So, total is difference in slopes (which is positive) + difference in appreciations.
  • Expectation hypothesis implies expected difference in appreciations cancels difference in slopes.
  • Empirically, average difference in appreciations actually adds a bit to difference in slopes.
    • Peso (backwardation) actually appreciates a little.
    • Euro (contango) actually depreciates a little.