Carry Trade Scanner: Rank Forex Pairs by Interest Rate Differential

What is a carry trade scanner?

A carry trade profits from the interest rate gap between two currencies. You go long the higher-yielding currency and short the lower-yielding one, collecting the daily swap (rollover interest) for holding the position overnight. A carry trade scanner automates the search for these opportunities: it pulls each currency's central bank policy rate, computes the differential for every tradable pair, and ranks them so the strongest carries surface first.

This tool scans every major, minor, and exotic pair in its dataset. For each pair it shows the base and quote policy rates, the differential, the carry direction, an estimated daily swap per standard lot, the annual carry percentage, and a risk-adjusted score. It also includes a portfolio builder so you can combine several carry positions and see net currency exposure and a diversification score.

How do you use the carry trade scanner?

1. Review the Rankings table. Pairs are sorted by carry strength by default, with the largest differentials at the top.
2. Use the Filter buttons to narrow the list to All, Major, Minor, Exotic, or High Carry (pairs with an absolute differential of 2% or more).
3. Use the Sort buttons to order by Carry (absolute differential), Risk-Adj (carry per unit of assumed volatility), or Pair (alphabetical).
4. Set your Account size (default $10,000). This drives the suggested 1%-risk position sizing shown in the detail panel.
5. Click any row to open its detail panel: central bank context, suggested lot size, daily and annual carry, and a rate-trend risk note.
6. Click + Add to drop a pair into the Portfolio Builder, adjust lots, and read the combined daily carry, annual percentage of account, currency exposure, and diversification score.

The colored bar on each row flags carry strength: strong (differential ≥ 5%), moderate (≥ 2%), low (≥ 0.5%), or neutral (below 0.5%).

How is the carry and swap calculated?

For each pair the tool reads the base and quote central bank rates, then computes:

• Differential = base rate − quote rate. If positive, the carry direction is long; if negative, it is short. Ranking and the annual carry percentage use the absolute value.
• Daily swap per standard lot = (absolute differential ÷ 365) × contract size ÷ 100. With a 100,000-unit contract, that is about $2.74 per day for every 1% of differential.
• Annual carry % = the absolute differential itself (the yearly interest spread on notional).
• Risk-Adjusted score = annual carry % ÷ estimated volatility, where volatility is a fixed proxy by category: 8 for majors, 10 for minors, 18 for exotics.

Rates load from a central bank rates file. Currencies not in that file use built-in fallback estimates (for example TRY 42.50%, ZAR 7.75%, MXN 10.50%). Several high-risk currencies carry an explicit warning (TRY and BRL are flagged extreme/high risk) because their currency risk can dwarf the interest income.

How does the position sizing and portfolio builder work?

The detail panel suggests a position that risks 1% of your account. It assumes a stop distance of (estimated volatility × 10) pips and a pip value of pip size × contract size, then sizes lots as risk amount ÷ (stop pips × pip value), with a 0.01 lot minimum. Because the volatility proxy is large, suggested lots are deliberately conservative.

The Portfolio Builder adds pairs at a default 0.10 lots each. It sums the daily carry across positions, multiplies by 365 for the annual figure, and expresses it as a percentage of your account. It nets long and short lots per currency to show currency exposure, then scores diversification as the number of distinct currencies used × 15, capped at 100. Concentrated bets on one or two currencies score low; spreading across more currencies raises the score.

Worked example: AUD/JPY carry on a $10,000 account

AUD/JPY is a classic carry pair. With AUD at 3.85% and JPY at 0.50%:

• Differential = 3.85 − 0.50 = +3.35%, so the carry direction is long (buy AUD, sell JPY).
• Daily swap per lot = (3.35 ÷ 365) × 100,000 ÷ 100 = $9.2 per standard lot per day.
• Annual carry % = 3.35%.
• Risk-Adjusted = 3.35 ÷ 10 (minor volatility proxy) = 0.34.

In the detail panel with a $10,000 account, 1% risk = $100. Stop = 10 × 10 = 100 pips; pip value = 0.01 × 100,000 = $1,000. Suggested lots = 100 ÷ (100 × 1,000) = 0.001, raised to the 0.01 minimum. That gives a daily carry of about $0.1 and an annual carry of roughly $34, about 0.3% of the account. Adding AUD/JPY to the portfolio at the default 0.10 lots instead yields about $0.9 daily, $335 annually, or 3.4% of a $10,000 account.

Why central bank rate trends matter for carry

The interest rate differential a carry trade earns is not fixed. It shifts every time either central bank changes policy, which is why the direction of rate trends matters as much as the current gap.

• Diverging policy (widening differential): the higher-rate central bank is still tightening while the lower-rate one is easing or holding. The carry tends to grow and the higher-yielding currency often appreciates as the gap widens. This is the most favorable backdrop for a carry trade.
• Converging policy (narrowing differential): the higher-rate central bank starts cutting while the lower-rate one starts hiking. The carry shrinks, and markets often move the exchange rate against the position before the rate change even happens, as expectations adjust in advance.

The scanner's detail panel shows each central bank's current rate, trend (tightening, easing, or holding), and policy bias so you can judge whether a differential is likely to widen, hold, or compress. A wide differential that is actively converging can be a worse setup than a smaller one that is stable or widening.

Why exotic carry pairs are so risky

Exotic pairs usually show the largest interest rate differentials, which makes them look like the best carry opportunities. The high yield exists precisely because the market demands compensation for outsized risk, and that risk can erase years of accumulated carry in a single move.

• Currency depreciation: high policy rates often accompany high inflation, and the currency tends to weaken over time. The Turkish lira, for example, lost the large majority of its value against the US dollar over 2018–2023 despite very high interest rates, which is why the tool flags it as extreme risk.
• Political and fiscal instability: government changes, fiscal stress, or loss of central bank credibility can trigger sudden, sharp selloffs.
• Capital controls: some governments restrict foreign-exchange flows during crises, which can trap or devalue positions.
• Thin liquidity: wide spreads and shallow order books mean large slippage when many traders try to exit at once.

The scanner attaches explicit risk warnings to several high-yield currencies (for example the Turkish lira and Brazilian real) for exactly this reason: the headline carry can be wiped out by an adverse currency move far larger than the interest collected.

Carry trading versus directional trading

Carry trading is structurally different from directional speculation, and confusing the two leads to poor expectations.

The best carry environment is a calm, range-bound market where the exchange rate stays roughly flat while swap accrues each night. A strong trend can either add to or destroy carry returns, and a sharp reversal can cost more than many months of accumulated interest.

Diversifying a carry portfolio

Holding a single carry trade concentrates your outcome in one currency's fate. Spreading exposure across several positions reduces the chance that one shock erases the whole book, which is the idea behind the tool's portfolio builder and its diversification score.

• Avoid funding-currency concentration: if every position is funded by selling the same low-rate currency (for example all short JPY), a rally in that one currency hits every trade at once.
• Mix geographies and policy cycles: currencies driven by different economies and central banks are less likely to move together, which lowers correlation risk.
• Keep each position small: size individual trades modestly relative to the whole portfolio so no single pair dominates the result.
• Plan for tail risk: stop-losses or protective options can cap the damage from a sudden risk-off unwind.

The builder nets your long and short lots per currency, counts how many distinct currencies you are exposed to, and turns that count into a rough diversification score. It is a prompt to broaden exposure, not a guarantee of safety, since carry currencies can become correlated precisely during the crises that matter most.

Practical tips for executing a carry trade

1. Confirm the swap with your broker first. The scanner derives swaps from central bank rates only. Your broker's actual credit or debit differs because of markups, funding and liquidity premiums, and the tom-next rollover mechanism, and the long and short sides are priced separately. A pair with positive theoretical carry can still pay a negative swap at some brokers.
2. Enter when conditions are calm. Carry positions perform best in stable, risk-on markets. Avoid opening new exposure into volatility spikes or immediately before uncertain central bank decisions.
3. Give the trade room. Because the edge comes from holding over time, carry trades generally use wider stops than short-term directional trades so normal noise does not close them prematurely.
4. Scale in. Building a position over several days or weeks, rather than entering all at once, reduces the impact of poor timing on any single entry.
5. Watch the central bank calendar. Rate decisions can change the differential overnight, so know when the relevant meetings fall before committing to a long hold.

When carry trades are most dangerous

Carry trades earn small, steady income but are exposed to sudden, violent reversals during risk-off events, which is why they are sometimes described as picking up pennies in front of a steamroller. Historically, the strategy has shown roughly equity-like average returns but with strongly negative skew, meaning occasional large losses concentrated in crises rather than spread evenly. Documented unwinds include the 1998 LTCM-era yen surge, the 2008 yen carry unwind, the 2015 Swiss franc de-peg, and the 2020 COVID panic.

Conditions that historically coincide with carry-trade stress, and that warrant caution or reduced size, include:

• Elevated market fear, such as a sharply rising volatility index (VIX).
• Major central bank meetings with uncertain outcomes.
• Geopolitical crises or sudden risk-off shifts.
• Periods of thin liquidity, such as year-end and quarter-end.
• An inverted yield curve in the high-rate currency, which can signal that rate cuts (and a narrowing differential) lie ahead.

These are heuristics, not precise triggers. The common thread is that carry unwinds happen when many leveraged holders rush to exit at the same time, so conservative sizing and predefined stops matter far more than squeezing out the last basis point of yield.

How broker swaps differ from the scanner's estimate

The scanner reports a theoretical carry built only from central bank policy-rate differentials. The swap your broker actually credits or debits each night will differ, sometimes substantially, for several reasons:

• Broker markup: brokers add a margin to the underlying funding rate, which reduces the carry you keep and is applied to each side of the trade.
• Tom-next rollover: swaps are derived from the tom-next forward points in the interbank market, which fluctuate daily and can differ from a simple rate-differential calculation.
• Asymmetric long and short rates: the swap paid on a long position and the swap charged on the corresponding short position are quoted separately and are not mirror images.
• Wednesday triple swap: because spot forex settles two business days forward (T+2), most brokers apply three days of swap on Wednesday to cover the weekend, so holding through the Wednesday rollover earns or costs three nights of swap at once.
• Swap-free accounts: swap-free (Islamic) accounts pay and charge no daily interest, which removes the carry entirely and makes a traditional carry trade unworkable on that account type.

Always verify the live swap on the specific pair with your own broker before committing to a carry position, and treat the scanner's figures as a ranking and planning estimate rather than the exact amount you will receive.

Frequently Asked Questions

• How is the daily swap on a carry trade estimated?

  The scanner estimates daily swap per standard lot as (absolute interest rate differential ÷ 365) × contract size ÷ 100. For a 100,000-unit lot that works out to roughly $2.74 per day for each 1% of differential. It is an estimate from central bank rates only and excludes broker markups, liquidity premiums, and funding costs, so your broker's actual swap will differ.

• What does the Risk-Adjusted score mean?

  The Risk-Adjusted score divides a pair's annual carry percentage by an assumed volatility proxy based on its category: 8% for majors, 10% for minors, and 18% for exotics. A higher score means more carry per unit of expected risk. It lets you compare a high-yielding but volatile exotic against a steadier major on a roughly like-for-like basis rather than by raw yield alone.

• Which currency should I go long for a positive carry?

  Go long the currency with the higher central bank policy rate and short the one with the lower rate. The scanner computes base rate minus quote rate: if that differential is positive it labels the pair long for carry, if negative it labels it short. The direction shown already reflects which side collects positive rollover interest on that pair.

• Why are the scanner's swap rates different from my broker's?

  The tool derives swaps purely from central bank interest rate differentials. Real broker swaps add markups, liquidity and funding premiums, and tom-next adjustments, and they differ between long and short sides. The page states this explicitly and advises verifying with your broker. Treat the scanner's figures as a ranking and planning estimate, not the exact credit or debit you will receive.

• What is the diversification score in the portfolio builder?

  The portfolio builder counts the distinct currencies your positions touch (after netting long and short lots) and scores diversification as that count × 15, capped at 100. A single pair touches two currencies for a score of 30; spreading across more currencies raises the score. It is a rough prompt to avoid concentrating an entire carry book in one or two currencies.

• Are carry trades risky?

  Yes. Carry trades earn steady small interest but face sudden, violent reversals during risk-off events, sometimes called picking up pennies in front of a steamroller. Currency moves can erase years of carry in days, as in the 2008 yen unwind. High-yield exotics like the Turkish lira are flagged extreme risk because depreciation can far exceed the interest collected.

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