Use of Currency Derivatives by Arbitragers

Arbitrage is the simultaneous purchase and sale of identical or equivalent assets in different markets to exploit price differentials and secure a profit without net market exposure.

In the currency context, the asset is a foreign‑exchange rate. An arbitrager watches the spot market, the forward market, and the derivatives market (futures/options) for mismatches that can be locked in using a single trade or a series of linked trades.

For the NISM exam, arbitrage questions often ask you to spot the mis‑pricing, calculate the profit, or identify which regulatory rule applies. Remember that arbitrage is risk‑free only when all legs are executed simultaneously and settlement risk is managed.

• Arbitrage eliminates market inefficiencies, helping prices converge.
• It is distinct from speculation, which accepts market risk for potential upside.

Three recognised arbitrage strategies are covered in the NISM syllabus: Covered Interest Arbitrage (CIA), Uncovered Interest Arbitrage (UIA) and Triangular Arbitrage (TA). Each exploits a different pricing relationship.

Covered Interest Arbitrage uses a forward or futures contract to lock in the future exchange rate, eliminating exchange‑rate risk. Uncovered Interest Arbitrage relies on the expectation that the spot rate will move in line with interest‑rate differentials, leaving the trader exposed to spot‑rate risk.

Triangular Arbitrage involves three currency pairs and exploits inconsistencies in cross‑rates. It is executed entirely in the spot market, making it the fastest arbitrage but also the most sensitive to execution latency.

Covered Interest Arbitrage (CIA) begins with borrowing in the currency with the lower interest rate, converting the amount at the spot rate, investing in the higher‑rate currency, and simultaneously entering a forward contract to convert the proceeds back at a predetermined rate.

The profit emerges when the forward rate implied by market rates differs from the forward rate quoted in the market. The relationship that must hold in an efficient market is the Covered Interest Parity (CIP) condition.

In the NISM exam, you may be given spot rate (S), domestic interest rate (r_d), foreign interest rate (r_f) and forward rate (F). You will be asked to verify CIP or compute the arbitrage profit.

Uncovered Interest Arbitrage (UIA) follows the same borrowing‑and‑investing steps as CIA but omits the forward contract. The trader expects the future spot rate to move in line with the interest‑rate differential.

The expected spot rate (E[S_T]) can be approximated by rearranging the CIP formula without the forward component: E[S_T] ≈ S × (1 + r_d × t/360) / (1 + r_f × t/360). The key risk is that the actual spot rate may deviate, turning a theoretically risk‑free profit into a loss.

Exam questions often ask you to compute the expected profit and then compare it with the actual forward rate to decide whether UIA or CIA is more advantageous.

Triangular Arbitrage exploits inconsistencies among three currency pairs. Suppose the market quotes USD/INR, EUR/USD and EUR/INR. The implied cross‑rate for EUR/INR can be derived as (USD/INR) × (EUR/USD). If the quoted EUR/INR differs, an arbitrager can profit by converting INR → USD → EUR → INR.

The steps are: (1) Sell INR for USD at the spot USD/INR rate, (2) Use USD to buy EUR at EUR/USD, (3) Convert EUR back to INR at the quoted EUR/INR. The net INR received is compared with the initial INR outlay.

Because all legs are executed in the spot market, speed is critical. The NISM exam may present a table of rates and ask you to calculate the arbitrage profit per 1 Lakh INR.

SEBI treats arbitrage as a legitimate activity but imposes strict reporting and position‑limit rules for exchange‑traded currency derivatives. Arbitragers must maintain a minimum net‑position of INR 10 crore in the underlying spot market to qualify for the "Arbitrage” exemption under the margin framework.

All arbitrage trades must be executed through a SEBI‑registered broker and reported in the daily position‑statement. Failure to disclose the arbitrage intent can lead to classification as speculative trading, attracting higher margin requirements.

For the exam, remember that the "Arbitrage” exemption reduces the initial margin to 5 % of the contract value, but the broker must obtain a written declaration of arbitrage intent from the client.

Use the mnemonic CIT – Covered, Interest, Triangular – to recall the three arbitrage types quickly.

When a question provides spot, forward, and interest rates, first verify Covered Interest Parity. If the forward rate is higher than the CIP‑implied rate, Covered Interest Arbitrage yields profit; if lower, the opposite trade is profitable.

Common mistake: mixing up domestic and foreign rates. In INR‑USD arbitrage, INR is the domestic currency, so use the INR rate as r_d and the USD rate as r_f.

Always check the tenor unit (days vs months) and apply the 360‑day convention unless the question states otherwise.