FRM Exam Part I · Swaps

Swap Mechanics and Market Structure for FRM Part I

Updated 11 October 2026 · Fact-checked

A swap is an agreement between two parties to exchange cash flows on set dates, calculated on a notional principal. In a plain vanilla interest rate swap, one side pays fixed and the other pays floating, usually with net settlement. To solve questions, compute each leg, net them, and check who pays whom.

Understand Swap Mechanics and Market Structure

A swap is an over-the-counter contract in which two counterparties agree to exchange streams of cash flows over a set period. Each stream is calculated from a formula, such as a fixed rate or a floating reference rate, applied to an agreed notional principal.

The notional is only a calculation base. In an interest rate swap it is usually not exchanged. Only the interest amounts move, and they are normally netted, so one party pays the difference. In a currency swap, principal amounts are often exchanged at the start and the end, which is why the notional matters more there.

In a plain vanilla interest rate swap, one party pays a fixed rate and receives a floating rate. The other does the opposite. The floating rate is typically set at the start of each period and paid at the end. A swap can be seen as a series of forward contracts or as a fixed-rate bond swapped for a floating-rate bond. That is why you can transform a floating-rate liability into a fixed-rate one by entering a pay-fixed swap, and a fixed-rate asset into a floating-rate asset by entering a pay-fixed, receive-floating swap.

Swaps trade mainly over the counter (OTC). Dealers (large banks) quote a bid and an offer and sit between end users such as corporates, funds and insurers. Bilateral OTC swaps carry counterparty credit risk, often reduced by netting and collateral. Standardised swaps are increasingly centrally cleared: a central counterparty (CCP) becomes the buyer to every seller and the seller to every buyer, through novation. Cleared swaps require initial and variation margin.

The comparative advantage argument says two firms can both gain if one has a relatively better borrowing rate in fixed markets and the other in floating markets. Each borrows where it has the relative advantage, then they swap. The total gain equals the difference between the two spread differentials. Many authors note that this argument is open to question, because the floating-rate spread is reset as credit quality changes. The firm that borrows floating and swaps to fixed bears the risk that its floating spread will rise, so the apparent gain is partly illusory.

Key formulas to remember

Fixed payment per period: Fixed payment = Notional × fixed rate × (days in period ÷ day-count basis); For a simple annual or semiannual swap, use rate ÷ payments per year. Use the stated day count if given.
Floating payment per period: Floating payment = Notional × floating rate set at the start of period × accrual fraction; The rate is set at the start and paid at the end of the period (set in advance, paid in arrears).
Net settlement: Net payment = Fixed payment − Floating payment; The fixed payer pays this amount if positive. If negative, the fixed payer receives the absolute value.
Total comparative advantage gain: Total gain = |Spread difference in fixed market − Spread difference in floating market|; Gain is split by negotiation, and any dealer fee reduces what the two firms share.
Swap as bond portfolio: Value to fixed payer = B_float − B_fixed; Fixed payer is short a fixed-rate bond and long a floating-rate bond. Floating bond is worth par just after a reset.

How to solve Swap Mechanics and Market Structure questions

Use this method for any question on swap cash flows, transformations or market structure.

1Identify each party's position: who pays fixed, who pays floating, and on what notional.
2Find the accrual fraction for the period (for example 0.5 for semiannual) and any day-count rule given.
3Compute the fixed leg: notional × fixed rate × accrual fraction.
4Compute the floating leg using the rate set at the start of that period, not the rate at payment.
5Net the two legs and decide the direction of the payment.
6For transformation questions, combine the original loan or asset cash flows with the swap legs and check what remains. Floating components should cancel.
7For comparative advantage questions, find the two spread differences, take the gap, subtract any dealer fee, then split the gain.
8For market structure questions, decide whether the issue is bilateral credit risk (netting, collateral) or cleared (novation, margin, CCP).

Quickest way: Net the legs and cancel the floating

When to use it: Use for transformation and cash flow questions with a floating rate loan or asset.

Write the original position as a rate, such as pays LIBOR + 1.0%.
Add the swap: pay fixed X, receive floating. Floating terms cancel.
The result is the fixed rate plus any spread: X + 1.0%.
For net payment, use (fixed rate − floating rate) × notional × accrual fraction.
For comparative advantage, use total gain = |difference of the two spread gaps| − dealer fee. Then split the gain, for example divide by two if gains are shared equally.

Common mistakes in Swap Mechanics and Market Structure

Treating the notional principal as an amount that is exchanged in an interest rate swap.
Currency swaps do exchange principal, so the two get mixed up.
Fix: In a single-currency interest rate swap the notional is only used to calculate interest and is not exchanged.
Using the floating rate at the payment date instead of the reset date.
Students assume the payment uses the latest rate.
Fix: The floating rate is set at the start of the period and paid at the end.
Ignoring the accrual fraction and applying an annual rate to a semiannual payment.
Rushing through the arithmetic.
Fix: Multiply by the period fraction, such as 0.5 for semiannual, or use the stated day count.
Confusing who gains in comparative advantage and forgetting that the gain is the difference of the spread differentials.
Students compare absolute rates instead of spreads.
Fix: Compute the spread difference in each market and subtract. Subtract any dealer fee before splitting.
Saying central clearing removes all counterparty risk.
The CCP is described as guaranteeing trades.
Fix: Clearing replaces bilateral exposure with exposure to the CCP, backed by margin and a default fund. Risk is concentrated, not eliminated.
Mixing up pay-fixed and receive-fixed when hedging.
Direction is not linked to the underlying exposure.
Fix: A floating-rate borrower who wants certainty pays fixed and receives floating. A fixed-rate bond holder who wants floating income also pays fixed and receives floating, because the swap's fixed payments offset the bond's fixed receipts and leave floating income.

Worked examples

Example 1

A company enters a 2-year swap with semiannual payments on a notional of USD 50 million. It pays a fixed rate of 4.0% per year and receives the floating rate. At the start of the first period the floating rate is 3.4% per year. What is the net payment at the end of the first period, and who makes it?

Show the solution

Accrual fraction = 0.5.
Fixed payment = 50,000,000 × 0.04 × 0.5 = USD 1,000,000.
Floating receipt = 50,000,000 × 0.034 × 0.5 = USD 850,000.
Net = 1,000,000 − 850,000 = USD 150,000.
The company is the fixed payer and the fixed leg is larger, so it pays the net amount.

Answer: The company pays a net USD 150,000.

Example 2

A firm has a floating-rate loan at LIBOR + 1.2%. It enters a swap in which it pays 5.0% fixed and receives LIBOR. What is its effective borrowing rate, and what risk has it removed?

Show the solution

Loan cost: pays LIBOR + 1.2%.
Swap: pays 5.0% and receives LIBOR.
Net = LIBOR + 1.2% + 5.0% − LIBOR.
LIBOR cancels, leaving 6.2%.

Answer: The effective rate is a fixed 6.2%, so the firm has removed floating-rate interest exposure.

Exam tips

Read the direction carefully: pay-fixed versus receive-fixed decides every sign.
Write the legs on separate lines before netting. This avoids sign errors.
Know the contrast between bilateral OTC (netting, collateral, credit risk) and cleared (novation, margin, CCP).
For comparative advantage, compute spread differences first. Do not compare absolute rates.
Remember that interest rate swap notionals are not exchanged, while currency swap principals usually are.

Practice questions from Swaps

Swap Mechanics and Market Structure in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Swap Mechanics and Market Structure: frequently asked questions

What is notional principal in a swap?

It is the reference amount used to compute the payments. In an interest rate swap it is not exchanged. It only scales the interest legs.

What is the difference between OTC and centrally cleared swaps?

A bilateral OTC swap is a direct contract between two parties, which bear each other's credit risk unless collateral or netting is used. A cleared swap is novated to a CCP, which stands between the parties and collects initial and variation margin.

Why are swaps usually settled net?

Both legs are in the same currency and fall on the same dates, so only the difference needs to move. This reduces payment flows and credit exposure.

How does a swap transform a liability?

A pay-fixed, receive-floating swap turns a floating-rate loan into an effectively fixed-rate one. A pay-floating, receive-fixed swap does the reverse.