# How to build a carry trade: yield, swap and unwind risk > A carry trade earns the interest difference between two currencies — and survives on risk rules, because the unwind is violent. Here is how to construct one properly. - Canonical URL: https://forextradingcommunity.com/news/how-to-build-a-carry-trade/ - Type: Guide - Published: 2026-09-19 - Updated: 2026-09-19 - Publisher: Forex Trading Community (https://forextradingcommunity.com), FTC Editorial Team - Currencies: JPY, USD The carry trade is the market's oldest income strategy: borrow a low-yield currency, invest in a high-yield one, and earn the interest difference every night. The income is real, the mechanics are simple, and the risk — the unwind that reverses the whole position violently when the market's mood turns — is the reason most carry traders eventually give the income back. Building the trade properly means building the risk rules first and treating the yield as what it actually is: compensation for a risk that will arrive. This guide explains the carry trade's construction, the pair selection and the risk framework. The mechanics are in [carry trade explained](/news/carry-trade-explained/); the unwind in [the carry unwind explainer](/news/why-carry-trades-unwind/). ## What the trade actually is A carry trade has three parts. The trader borrows — sells — a low-yield funding currency, buys a high-yield currency or asset, and collects the interest difference through the swap, credited daily. The trade's profit is the yield; its risk is the exchange rate: if the funding currency strengthens against the investment, the exchange-rate loss can erase years of interest in days. The trade's defining feature is that everyone runs versions of it. The crowding is why the income exists — the market pays a premium to those willing to hold the risk — and why the unwind is violent: when the trade reverses, the exits all flow through the same door. The [carry unwind explainer](/news/why-carry-trades-unwind/) covers the mechanics in full. ## Choosing the pair The pair selection decides the trade's economics, and three questions frame it: **The yield gap.** The interest difference between the two currencies is the income — the wider the gap, the larger the daily swap. The gap's size is the first filter: a pair with a thin gap does not pay enough for the risk. The [swap and trading costs guide](/news/spread-commission-and-swap-trading-costs/) shows how to read the swap in the platform. **The funding currency's risk profile.** The currency you borrow carries the unwind risk, and the market's classic funding currencies — the yen, the franc — are exactly the ones that spike when the carry unwinds. Borrowing the yen means the trade's risk is intervention-shaped as well: the authorities' yen support ([report](/news/japan-us-joint-yen-intervention-2026/)) is a direct threat to the trade's exchange-rate side. The [yen haven explainer](/news/why-the-yen-is-a-safe-haven/) covers the funding side's behaviour. **The investment currency's carry quality.** The high-yield side's quality matters: a high-yield major like the aussie carries different risks from an EM currency with crisis exposure. The [EM explainer](/news/how-em-currencies-differ/) covers the high-yield side's risk premia — the yield is higher exactly because the crisis risk is real. The practical starting point for most retail traders is the major-pair version: the yen as funding against a higher-yielding major, or the dollar against a higher-yielding EM — with the trade's size and stop rules doing the risk management the pair selection cannot. ## The construction, step by step The trade's construction has five steps: 1. **Measure the swap honestly.** The platform's symbol specification lists the long and short swap rates — the trade's daily income, with the broker's mark-up included. Multiply by the holding period's nights, including the triple days. The [rollover explainer](/news/what-is-rollover/) covers the swap's mechanics. 2. **Set the exchange-rate risk first.** Before the income, decide the trade's exit: the stop-loss level where the exchange-rate loss outweighs the yield's value, and the structure that anchors it. The [stop-loss guide](/news/where-to-place-a-stop-loss/) supplies the anchoring logic — the carry trade's stop is its most important line. 3. **Size for the unwind, not the income.** The position must survive the trade's worst case: the funding currency's spike during an unwind, which can be hundreds of pips in days. The size follows the risk-first arithmetic from [position sizing](/news/position-sizing-and-risk-per-trade/) — and the carry trade's version uses the unwind scenario as the stop distance. 4. **Plan the exit triggers.** The unwind's early warnings are the trade's exit signals: volatility rising, the funding currency strengthening, the risk mood turning. The [risk sentiment guide](/news/how-to-read-risk-sentiment/) supplies the five-minute read; the trade's rules must say which signals end it. 5. **Track the income against the risk.** The journal records the swap earned and the drawdowns survived, so the trade's true economics — the yield minus the unwind losses — stay visible. The [journal guide](/news/how-to-keep-a-trading-journal/) has the fields. ## The risk rules that make it survive The carry trade's survival rules are the difference between the strategy and the disaster: **Never size for the income.** The yield's size is not the position's justification — the unwind risk is, and the position must be small enough that the worst unwind is a setback, not an end. The trade's most common failure is the position sized to the yield's promise rather than the unwind's threat. **Have the exit before the entry.** The unwind's exit rules are written before the trade exists: the volatility trigger, the funding-currency spike, the risk-mood turn. When the warnings fire, the trade closes — the [carry unwind explainer](/news/why-carry-trades-unwind/) lists the signatures. **Treat the yield as compensation, not income.** The swap is the market paying for the risk you are holding — and the payment is never enough at the extremes. The mental frame matters: the carry trade is a risk trade with a yield attached, not an income stream with a risk footnote. ## The current environment's read The current cycle is the carry trade's cautionary display: the yen carry against the dollar's near-4% ([report](/news/fed-raises-rates-september-2026/)) pays a wide gap — and carries the standing intervention threat ([report](/news/japan-us-joint-yen-intervention-2026/)) plus the BoJ's normalisation ([preview](/news/bank-of-japan-september-2026-preview/)) as its two tails. The trade's economics are live and tempting, and its risk rules are the only thing standing between the trader and the unwind. The [BoJ dilemma analysis](/news/boj-september-2026-intervention-dilemma/) maps the tails. The carry trade is the market's most honest bargain: steady yield in exchange for the unwind's violence. Build the risk rules first, size for the worst case, and the trade becomes a durable strategy instead of a slow-motion disaster. ## Sources - [Bank of Japan](https://www.boj.or.jp/en/) - [Bank for International Settlements](https://www.bis.org/) ## Common questions ### What is a carry trade in forex? Borrowing a low-yield currency, investing in a high-yield one, and earning the interest difference through the daily swap. The profit is the yield; the risk is the exchange rate reversing. ### How do I choose a carry trade pair? By the yield gap's size, the funding currency's unwind risk, and the investment currency's quality. The wider gap pays more — and the riskier funding currencies spike harder when the trade unwinds. ### What is the biggest risk in a carry trade? The unwind: the funding currency strengthens violently when risk appetite turns, and the exchange-rate loss erases months of yield in days. The risk is structural, not occasional. ### How should I size a carry trade? For the unwind scenario, not the income: the position must survive the funding currency's worst spike. The risk-first sizing arithmetic applies with the unwind as the stop distance. ### Does the carry trade still work when intervention risk is live? The yield gap is still there, but the intervention threat is a direct risk to the exchange-rate side. The trade works only with the exit rules and the sizing built for exactly that tail. --- This article is for information only and is not financial advice. Trading forex and CFDs carries a high risk of losing money.