Direct answer
A carry trade is a forex position built around the idea that one currency may offer higher interest than another. The basic goal is to receive the interest advantage (often described as “carry”) while managing the fact that the exchange rate can move against the position.
Carry trade is conceptually simple, but its real-world results are not. Even when the interest-rate difference is stable in principle, performance can change quickly due to exchange-rate changes, funding and financing costs, and trading frictions.
Mechanism and definition
At a high level, a carry trade involves two legs:
- You hold a currency with a relatively higher interest rate.
- You fund (or effectively short) a currency with a relatively lower interest rate.
The “carry” part is the interest-rate differential. In practice, the exact realized amount depends on assumptions such as: which rates are used to compute interest, how often funding is applied, and what additional costs occur (spreads, commissions, rollover/financing charges, and potential slippage). Because these details vary by setup and jurisdiction, you should treat any simplified calculation as an approximation unless you specify the method.
A simple illustrative model (no live prices): suppose you invest an amount that earns an annualized interest rate higher than the funding rate by 3%. If the exchange rate does not change, you would expect a return component related to that differential. But if the exchange rate moves enough to create a loss on the currency conversion, the interest advantage can be reduced or exceeded.
Example with clear assumptions (not a prediction)
Assume:
- You earn interest equivalent to +3% per year from the higher-rate currency.
- Your financing leg costs are already included in that +3% net differential.
- You ignore transaction costs and execution effects for the moment.
Under these assumptions, a carry trade would have a positive carry component if the higher-rate currency remains stable versus the funding currency. If instead the higher-rate currency depreciates by more than the interest advantage over the holding period, the translation loss can dominate.
Limitations and failure modes
Carry trade can fail in several common ways:
- Exchange-rate “catch-up”: sudden moves can overwhelm carry. This is often discussed as the market repricing the expected risk or macro outlook.
- Cost drag: spreads, commissions, and financing-related charges can reduce the realized differential.
- Leverage sensitivity: when positions are leveraged, smaller exchange-rate moves can produce larger percentage losses.
- Model mismatch: using an interest-rate differential as if it directly equals realized returns can be misleading if the interest calculation method, timing, or costs differ from the assumptions.
Because of these limitations, historical relationships between interest differentials and outcomes do not establish that future results will follow the same pattern.
Verification and next question
To independently verify claims about carry trades, check the following:
- What exact interest-rate inputs are assumed, and how are they translated into realized financing or returns?
- Which costs are included (spreads, commissions, rollover/financing, and execution slippage) versus excluded?
- How sensitive results are to exchange-rate movements using scenarios based on your own assumptions.
A useful next question is: how does carry change when markets shift from stable conditions to fast repricing? That helps you assess whether the interest advantage is likely to be offset by exchange-rate risk.