Contract Specification of Exchange-Traded Currency Options
This sub‑topic explains the contract specification of exchange‑traded currency options, the backbone of any options trade on Indian exchanges. Knowing each specification helps you read the contract sheet, calculate payoffs, and avoid common exam mistakes. The content links directly to SEBI‑mandated terminology and NISM’s exam focus on contract details. Mastery of these specs is essential for both the certification and real‑world trading.
Learning Objectives
- 1Identify all elements that define a currency option contract on NSE/MCX.
- 2Interpret quote conventions and understand how they affect pricing.
- 3Distinguish between American and European exercise styles and their exam implications.
- 4Apply contract specifications to compute option pay‑offs and margin requirements.
Contract Specification Overview
A currency option contract on an Indian exchange is a standardized agreement that specifies the rights and obligations of the buyer and seller. The standardisation covers the underlying currency pair, contract size (lot), strike price increments (tick size), expiry date, settlement method, and margin requirements. Because every parameter is fixed by the exchange, traders can focus on pricing and risk rather than negotiating terms.
SEBI requires that each contract sheet display these specifications clearly. For the NISM exam, you will often be asked to match a given contract description with the correct parameter, such as identifying the lot size for an INR/USD option or the tick size for a EUR/INR call. Understanding the hierarchy—pair → lot → tick → strike → expiry—helps you answer such questions quickly.
Typical exam traps include confusing the “contract size” (the notional amount of the underlying) with the “lot size” (the minimum tradable quantity). Remember that the contract size is expressed in the base currency of the pair, while the lot size is the number of such contracts that can be bought or sold in a single order.
- Contract Size – Notional amount of base currency per contract (e.g., USD 100,000).
- Lot Size – Minimum number of contracts that can be executed (often 1 lot = 1 contract).
Students often treat the two as interchangeable. In reality, the contract size defines the notional exposure, while the lot size tells you the smallest tradable unit. The NISM question will usually give one and ask for the other.
Underlying Currency Pair & Quote Conventions
The underlying pair is always quoted in the format base/quote. In India, most currency options use INR as the quote currency, e.g., USD/INR or EUR/INR. The price indicates how many Indian rupees are needed to buy one unit of the base currency.
Quote conventions affect how you read the spot price (S) and strike price (K). For a USD/INR option, a spot of 82.50 means 1 USD = 82.50 INR. If the pair were quoted INR/USD (rare on Indian exchanges), the interpretation would be reversed, leading to calculation errors.
For the exam, remember that the base currency is always the first code. The strike price is expressed in the quote currency per unit of base currency, and the contract size is denominated in the base currency.
- Base Currency – Currency being bought or sold (first code).
- Quote Currency – Currency used to price the base (second code).
Quote Conventions for Common Currency Pairs on Indian Exchanges
| Pair | Base Currency | Quote Currency | Typical Spot Representation |
|---|---|---|---|
| USD/INR | US Dollar | Indian Rupee | 1 USD = 82.50 INR |
| EUR/INR | Euro | Indian Rupee | 1 EUR = 89.30 INR |
| GBP/INR | British Pound | Indian Rupee | 1 GBP = 103.20 INR |
Option Type, Exercise Style & Moneyness
Currency options can be either calls (right to buy the base currency) or puts (right to sell the base currency). The exercise style is almost always European on Indian exchanges, meaning the option can be exercised only on the expiry date. A few niche contracts may allow American style, but they are explicitly mentioned in the contract sheet.
Moneyness describes the relationship between the spot price (S) and strike price (K). An option is in‑the‑money (ITM) when exercising would be profitable: call ITM if S > K, put ITM if S < K. It is out‑of‑the‑money (OTM) when the opposite holds, and at‑the‑money (ATM) when S = K. The NISM exam frequently asks you to classify an option given S and K.
Remember that the premium you pay is separate from moneyness; a deep‑ITM option will have a higher premium, but the payoff calculation remains the same. Knowing the exercise style helps you answer questions on early exercise rights.
- European – Exercise only on expiry.
- American – Exercise any time up to expiry (rare in India).
Unless the contract sheet explicitly states ‘American’, treat the option as European. The exam penalises the opposite assumption.
Expiration, Settlement and Contract Months
Expiration dates for Indian currency options are fixed on the third Thursday of the contract month. If the Thursday is a holiday, the expiry moves to the previous business day. The contract month is the month in which the option expires, and contracts are listed for the nearest three months (e.g., Jan, Feb, Mar). Understanding this schedule is crucial for time‑value calculations.
Settlement is cash‑based: on expiry, the difference between the spot and strike (multiplied by contract size) is settled in INR. Physical delivery of the underlying foreign currency does not occur for standard exchange‑traded options.
Exam questions may present a scenario like ‘an EUR/INR call expiring on 21‑Mar‑2024’. You must recognise that 21‑Mar‑2024 is the third Thursday of March 2024, confirming the contract month and settlement method.
- Cash Settlement – Net cash payment in INR based on payoff.
- Third Thursday Rule – Standard expiry convention.
Typical Expiry Dates (Third Thursday) for 2024
Contract Size, Tick Size, and Premium
Contract size defines the notional amount of the base currency per option contract. For example, a USD/INR option typically has a contract size of USD 100,000, meaning each contract represents a right on 100,000 USD. Tick size is the minimum price movement allowed for the option premium and is expressed in paise per INR of premium. A common tick size is 0.05 INR per 1,000 INR of premium.
The premium you pay (or receive) is quoted per unit of contract size. If the premium is 0.25 INR and the contract size is USD 100,000, the total premium payable is 0.25 × 100,000 = 25,000 INR. The exam often asks you to compute the total premium given the per‑unit premium and contract size.
Remember that the premium is separate from the intrinsic value (payoff). A deep‑OTM option may have a very low premium, while an ITM option’s premium includes both intrinsic value and time value. Mis‑reading the tick size can lead to incorrect premium calculations.
- Contract Size – Notional amount of base currency per contract.
- Tick Size – Minimum price increment for the premium.
Where:
S= Spot price of the base currency in quote currency (e.g., INR per USD)K= Strike price of the option in the same units as SWorked Example
Given S = 83.00 INR/USD and K = 80.00 INR/USD: Step 1: Compute S - K = 83.00 - 80.00 = 3.00 Step 2: Payoff = max(3.00, 0) = 3.00 INR per USD Step 3: For a contract size of 100,000 USD, total payoff = 3.00 × 100,000 = 300,000 INR. Verification: max(83.00 - 80.00, 0) = 3.00.
Scenario
An investor buys one EUR/INR European call option with a strike of 89.00 INR/EUR. On expiry, the spot rate is 92.50 INR/EUR. The contract size is EUR 100,000.
Solution
Step 1: Determine intrinsic value: Spot - Strike = 92.50 - 89.00 = 3.50 INR per EUR. Step 2: Since the option is a call, payoff per EUR = max(3.50, 0) = 3.50 INR. Step 3: Multiply by contract size: 3.50 × 100,000 = 350,000 INR. Step 4: The investor receives a cash settlement of 350,000 INR. No further calculation of premium is needed for payoff.
Conclusion
The example shows how the payoff formula directly translates spot‑strike difference into cash settlement using the contract size. Remember to apply the max function to avoid negative payoffs.
Margin Requirements & Position Limits
SEBI mandates an initial margin (also called premium margin) for each currency option contract. The margin is a percentage of the contract value, typically 15‑20% of the notional exposure, and is collected by the clearing corporation. Maintenance margin must be maintained throughout the trade’s life; a breach triggers a margin call.
Position limits restrict the maximum open interest a single participant can hold in a particular contract month. For example, a participant may hold no more than 5% of the total open interest in the USD/INR March contract. Exceeding limits leads to regulatory penalties and may be asked in scenario‑based questions.
When answering exam items, first compute the notional exposure (contract size × spot price), then apply the margin percentage to find the required margin. Also, verify that the proposed position does not breach the open‑interest limit.
- Initial Margin – Up‑front cash collateral, usually 15‑20% of exposure.
- Open‑Interest Limit – Maximum % of total market exposure per participant.
Do not confuse the premium paid with the margin requirement. Premium is the option price; margin is a separate collateral based on notional exposure.
Summary of Specification Parameters
Key Contract Specification Elements for Currency Options
| Parameter | Typical Value / Description | Exam Note |
|---|---|---|
| Underlying Pair | e.g., USD/INR, EUR/INR | Base‑quote order matters |
| Contract Size | Base currency amount per contract (e.g., USD 100,000) | Used to compute total premium/payoff |
| Lot Size | Minimum tradable contracts (usually 1) | Do not mix with contract size |
| Tick Size | Minimum premium increment (e.g., 0.05 INR per 1,000 INR) | Affects premium calculation |
| Strike Price | Quoted in quote currency per unit of base | Compare with spot for moneyness |
| Expiration | Third Thursday of contract month | Check holiday rule |
| Settlement | Cash‑settled in INR | No physical delivery |
| Exercise Style | European (default) / American (rare) | Assume European unless stated |
| Margin | 15‑20% of notional exposure | Separate from premium |
| Position Limit | Typically ≤5% of total OI | Watch for regulatory breach |
⭐Exam Takeaways
- Contract size is the notional amount of the base currency; lot size is the minimum number of contracts you can trade.
- Quote conventions always list the base currency first; the strike and spot are expressed in the quote currency per unit of base.
- Indian currency options are predominantly European; exercise only on the third Thursday of the contract month.
- Payoff for a call = max(Spot – Strike, 0) and for a put = max(Strike – Spot, 0); multiply by contract size for cash settlement.
- Margin is a percentage of notional exposure (15‑20% typical) and is distinct from the premium paid.
- Open‑interest limits usually cap a participant’s exposure to about 5% of total market OI for a given contract month.
- Tick size determines the smallest premium movement; always use it when converting per‑unit premium to total premium.
- Remember the third‑Thursday expiry rule and the cash‑settlement mechanism for all standard currency options on Indian exchanges.
Practice Questions
8 questions on Contract Specification of Exchange-Traded Currency Options
What does "contract size" represent in an exchange‑traded currency option?
What is the typical exercise style for currency options on Indian exchanges?
A USD/INR European call has spot 84 INR/USD, strike 80 INR/USD and a contract size of 100,000 USD. What is the total cash payoff at expiry?
If the premium quoted for a EUR/INR option is 0.30 INR per unit and the contract size is 100,000 EUR, what is the total premium payable?
An EUR/INR European put has strike 90 INR/EUR. At expiry the spot is 88 INR/EUR and the contract size is 100,000 EUR. What cash settlement does the holder receive?
A USD/INR option expires in March 2024. The third Thursday of March 2024 is the 21st, which is a holiday. On which date does the contract actually expire?
Which statement correctly describes "lot size" for currency options?
An investor writes a USD/INR call. Contract size is 100,000 USD, spot at initiation is 82 INR/USD, strike is 85 INR/USD, and the exchange requires an initial margin of 15 % of notional exposure. What is the minimum margin required?