Direct answer
Rollover for “Pair News Sensitivity” is not a separate new formula. Conceptually, it is still the interest-cost or interest-income on an open forex position, expressed through (1) the interest-rate inputs implied by the two currencies, (2) adjustments the provider applies in its swap/rollover terms, and (3) a time convention such as triple-swap on certain days. Pair News Sensitivity mainly changes expectations and volatility around those rates, so rollover effects may move when markets reprice rate expectations—but the core mechanics of rollover calculation remain the same.
Mechanism and definition
Rollover (swap) in FX is the adjustment applied when you hold a leveraged spot forex position from one trading day to the next. In simplified terms, it represents the interest-rate differential between the two currencies in the pair, converted into a per-day amount for the position size.
To explain rollover calculation for Pair News Sensitivity, separate three layers:
- Stable interest-rate differential mechanics (conceptual input)
- Forex spot positions are conceptually linked to the difference between short-term interest rates of the two currencies.
- The “direction” matters: holding a long position in one currency generally carries different interest than holding a long position in the other currency.
- Assumption for examples: If currency A has a higher interest rate than currency B, then the position that is “long A” and “short B” typically bears rollover cost, while the opposite direction typically receives rollover (how this appears in your account depends on the provider’s sign convention).
- Broker/provider rollover terms (mechanical output)
- Providers publish swap/rollover rates for each instrument and trade direction (buy vs sell), often as a daily value or as a per-unit/percentage representation.
- These published rates embed conversion factors and implementation choices. Common practical causes of differences between “idealized” interest differential and what you see include rounding, unit conventions, and internal handling of liquidity.
- Assumption for verification: Use the swap values shown on the platform for your exact pair, direction, and account.
- Triple-swap convention (time rule)
- Many providers apply a triple rollover on a specific day to account for non-trading days. Operationally, this means the daily rollover is multiplied for that day’s charge/credit.
- Assumption for example: If daily rollover is applied at X, the triple-swap day applies approximately 3×X for that day’s rollover event.
Evidence or checkable example (with explicit assumptions)
Because real swap rates vary by provider and account, the most reliable “independent verification” approach is to test the provider’s displayed rollover terms rather than estimating from public rate differentials.
Example using illustrative placeholders (not market data):
- Assume you hold a position with size S.
- Assume the provider shows a daily rollover rate of R per unit of your position (with sign + for credit and − for charge) for your trade direction.
- Then the expected rollover change from rollover on a normal day can be represented as:
- Rollover amount ≈ S × R (using the provider’s exact units and sign convention).
Now consider a day where the provider applies triple rollover:
- Triple-swap day rollover amount ≈ S × R × 3.
Where does Pair News Sensitivity fit?
- Pair News Sensitivity describes how sensitive a pair’s behavior may be to news-driven changes in expectations. When news shifts expected interest rates, the “interest differential outlook” changes.
- Even if market expectations move, your actual realized rollover is still determined by the provider’s current swap terms and the time convention. Therefore, Pair News Sensitivity can influence what you pay/receive in practice by changing the provider’s swap terms or by changing how much you care about holding overnight, but it does not replace the underlying rollover calculation mechanics.
Limitations and risks
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Rollover is provider- and account-dependent Swap/rollover terms are implemented by providers and may not match any simplified interest differential model. Two accounts can show different swap rates for the same pair due to contract and implementation differences.
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Sign and timing conventions can be confusing Whether you see a rollover as a “charge” or a “credit” depends on the provider’s sign convention and your trade direction. Also, rollover is tied to provider server time and the day boundary; your local calendar day may not align.