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Advanced Financial Management · Foreign Exchange Exposure and Risk Management

Arbitrage and Forex Risk Management Policy for CA Final AFM

Updated 5 October 2026 · Fact-checked

Arbitrage earns a risk-free profit from price mismatches. In triangular arbitrage, you compare a direct cross rate with the rate implied by two other quotes, then trade around the loop. In covered interest arbitrage, you compare the market forward with the interest-parity forward. Forex risk policy uses internal tools like netting, matching and leading-lagging first.

Understand Arbitrage and Forex Risk Management Policy

Arbitrage means earning a profit with no risk and no net investment by exploiting a price mismatch. In forex, the mismatch is between exchange rates in different markets, or between a forward rate and what interest rates imply. Traders act on it until the gap closes.

Triangular arbitrage uses three currencies. Two quotes imply a third (the cross rate). If the market quote for that third pair differs from the implied rate, you buy the currency that is cheap and sell it where it is dear, and finish in your starting currency. Start with INR, move through the other two currencies, and come back to INR. If you end with more INR than you began with, the loop works.

Covered interest arbitrage uses spot, forward and two interest rates. Interest rate parity says the forward rate should offset the interest differential. If the market forward is not equal to the parity forward, you borrow in one currency, invest in the other, and lock the exchange back with a forward contract. The forward cover makes the profit certain.

On the risk-management side, a firm first tries internal techniques. These cost little and need no outside contract. They reduce the exposure before you spend money on forwards, options or swaps. The main ones are invoicing in home currency, netting, matching, leading and lagging, and price adjustment. Whatever is left after this is the residual exposure, and you hedge only that using external tools.

A written forex risk policy sets who may take decisions, which exposures to cover, how much to cover, which tools to use, and how to report. Exams ask you to compute the arbitrage profit or the netted exposure, and then to advise.

Key rules to remember

Implied cross rate
A/C implied = (A/B) × (B/C)
Chain the quotes so the common currency cancels. Compare the result with the actual A/C quote.
Triangular arbitrage test
Start amount × rate 1 × rate 2 × rate 3 > Start amount ⇒ arbitrage
Convert every step in the correct direction (divide by a quote when buying the base currency with the quote currency, multiply when selling it). If the result is below the start, run the loop in reverse.
Interest rate parity forward
F = S × (1 + i quote × n) ÷ (1 + i base × n)
Quote currency is the one in which the rate is expressed (INR in USD/INR). n is the period in years. Use the same compounding basis for both rates.
Covered interest arbitrage test
Market forward ≠ parity forward ⇒ arbitrage
If market forward is below parity, the base currency is cheap forward: borrow base currency, invest in quote currency, buy base currency forward. If it is above parity, reverse it.
Net exposure
Net exposure = Σ receivables − Σ payables (in the same currency and date)
Netting offsets inflows against outflows. Only the net amount needs hedging.
Internal techniques list
Invoicing in home currency, netting, matching, leading and lagging, price variation, asset-liability management
Internal techniques come before external hedges such as forwards, futures, options and swaps.

How to solve Arbitrage and Forex Risk Management Policy questions

Use the same sequence for any arbitrage or exposure-management question. It keeps the direction of each trade clear and stops sign errors.

  1. 1Write all quotes in one clear format, for example INR per unit of foreign currency. Note whether bid and ask rates are given.
  2. 2Decide which test applies: three currencies mean triangular arbitrage; spot, forward and two interest rates mean covered interest arbitrage.
  3. 3Compute the benchmark: the implied cross rate for triangular, or the parity forward for covered interest.
  4. 4Compare it with the market quote. The difference tells you which currency is cheap and which is dear, and so the direction of the loop.
  5. 5Trade the loop step by step using a stated amount, and show each intermediate amount. Use the buy rate when you buy and the sell rate when you sell.
  6. 6For covered interest arbitrage, include the loan repayment with interest, the investment maturity value and the forward conversion. Profit is the difference at maturity in home currency.
  7. 7For exposure management, list inflows and outflows by currency and date, net them, then match or lead-lag where possible and hedge only the residual.
  8. 8State the conclusion in one line: arbitrage exists or not, the profit, and what the firm should do.

Quickest way: Compare, then cycle with a multiplier

When to use it: Use when the question gives a start amount and clean quotes, and you need only the profit or the direction.

  1. Multiply the three rates around the loop in one line, for example ₹ × (1 ÷ rate 1) × rate 2 × rate 3.
  2. If the result exceeds your start, the loop is profitable. If not, reverse it.
  3. For covered interest, compute the parity forward once and compare it with the market forward. Then trade a round amount such as USD 1,00,000 to get the profit in rupees.
  4. For netting, put currencies in columns and dates in rows, and subtract. Hedge only the leftover.

Common mistakes in Arbitrage and Forex Risk Management Policy

  • Multiplying when you should divide in a triangular loop

    Students do not track which currency is the base and which is the quote in each step.

    Fix: Write each rate as 'units of currency X per 1 unit of Y'. Dividing by a rate buys Y with X; multiplying sells Y for X.

  • Ignoring bid-ask spreads when the question gives them

    Students take a single mid rate to save time.

    Fix: Use the bank's buying rate when you sell currency to it and its selling rate when you buy from it. Do the full loop at these rates.

  • Using annual interest rates for a part-year forward

    The period is in months and the rate is quoted per annum.

    Fix: Convert the rate to the period first, for example 8% p.a. becomes 4% for six months, unless the question states compounding.

  • Running covered interest arbitrage in the wrong direction

    Students do not compare the market forward with the parity forward before trading.

    Fix: Find the parity forward first. If the market forward is below it, buy the foreign currency forward; if above, sell it forward.

  • Hedging gross exposure instead of net exposure

    Students forget that receivables and payables in the same currency and date offset each other.

    Fix: Net first. Hedge only the residual, and say that netting saves the cost of hedging the offset part.

  • Confusing netting with matching

    Both reduce exposure, so they look alike.

    Fix: Netting offsets inflows and outflows between group entities, often through a central treasury. Matching pairs inflows and outflows in the same currency and timing, often by choosing the currency of borrowing or payment to align with receipts.

Worked examples

Example 1

A treasury manager has ₹83,00,000. Quotes: USD/INR = 83.00; GBP/INR = 105.00; GBP/USD = 1.2800 (1 GBP = 1.28 USD). Ignore transaction costs. Is there a triangular arbitrage opportunity? If so, find the profit.

Show the solution
  1. Implied GBP/USD from the INR quotes = 105 ÷ 83 = 1.2651 (approx.).
  2. The market GBP/USD of 1.28 is higher, so GBP is dear in the USD market and cheap in INR. Buy GBP with INR, sell GBP for USD, sell USD for INR.
  3. Step 1: ₹83,00,000 ÷ 105 = GBP 79,047.62.
  4. Step 2: GBP 79,047.62 × 1.28 = USD 1,01,180.95.
  5. Step 3: USD 1,01,180.95 × 83 = ₹83,98,019 (approx.).
  6. Profit = ₹83,98,019 − ₹83,00,000 = ₹98,019 (approx.).

Answer: Arbitrage exists. Buy GBP with INR, sell GBP for USD, sell USD for INR, for a profit of about ₹98,019 on ₹83,00,000.

Example 2

Spot USD/INR is 83.00. The 6-month forward is 84.00. Six-month interest rates are 8% p.a. in India and 4% p.a. in the US (simple, use half the annual rate). Is there a covered interest arbitrage opportunity? Show the profit on a USD 1,00,000 borrowing.

Show the solution
  1. Parity forward = 83 × (1 + 0.08 × 0.5) ÷ (1 + 0.04 × 0.5) = 83 × 1.04 ÷ 1.02 = 84.63 (approx.).
  2. Market forward 84.00 is below parity 84.63, so USD is cheap forward. Borrow USD, invest in INR and buy USD forward.
  3. Borrow USD 1,00,000 and convert at spot: 1,00,000 × 83 = ₹83,00,000.
  4. Invest ₹83,00,000 in India for six months at 4%: ₹83,00,000 × 1.04 = ₹86,32,000.
  5. USD loan repayment = 1,00,000 × 1.02 = USD 1,02,000. Buy it forward at 84.00: 1,02,000 × 84 = ₹85,68,000.
  6. Profit = ₹86,32,000 − ₹85,68,000 = ₹64,000.

Answer: Yes. Borrow USD, convert to INR at spot, invest in India, and buy USD forward at 84.00 to repay. The risk-free profit is ₹64,000 at the end of six months.

Exam tips

  • Always show the benchmark first: the implied cross rate or the parity forward. Marks are given for the test, not just for the final profit.
  • Draw the loop as an arrow chain, for example INR → GBP → USD → INR, and write the rate beside each arrow.
  • In covered interest questions, state the loan, the investment and the forward cover as three separate lines. Examiners look for each.
  • For internal techniques, write definition, one-line example and the benefit. Then mention that the residual exposure is hedged externally.
  • If a question asks for a policy, cover objective, exposure identification, authority limits, hedge ratio, instruments and reporting.

Practice questions from Foreign Exchange Exposure and Risk Management

Arbitrage and Forex Risk Management Policy in other exams

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

Arbitrage and Forex Risk Management Policy: frequently asked questions

How do I know the direction of a triangular arbitrage?

Compute the implied cross rate from two quotes and compare it with the market quote. Buy the currency that is cheap in one market and sell it where it is dear. If your loop ends with less than you started with, run it in reverse.

How do I calculate covered interest arbitrage?

First find the parity forward using spot and the two interest rates for the period. Compare it with the market forward. Borrow in one currency, invest in the other, and cover the final conversion with a forward contract. Profit is the difference at maturity in one currency.

What is the difference between netting and matching?

Netting offsets inflows and outflows in the same currency, often across group companies, so only the net amount is exposed. Matching aligns inflows and outflows in currency and timing, for example by borrowing in the currency in which you earn revenue. Both are internal techniques.

What are the internal techniques of exposure management?

They are invoicing in home currency, netting, matching, leading and lagging, price variation and asset-liability management. You use them before external hedges such as forwards, futures, options and swaps. They cost little and reduce the amount you need to hedge.

What are leading and lagging?

Leading means paying or collecting earlier than due, and lagging means doing so later. A firm leads payments in a currency it expects to strengthen and lags payments in a currency it expects to weaken. For receivables, it does the opposite. It depends on a correct forecast, so it carries risk.