Introductory Context
"This topic provides the complete specification detail for USD/INR options as of the curriculum date -- always verify current specifications from NSE directly. The specifications are presented with worked examples that show exactly how each parameter affects actual trade mechanics, premium calculations, and P&L outcomes. "
Complete USD/INR Options Contract Specification
Underlying asset: USD/INR spot exchange rate, as published by the Foreign Exchange Dealers Association of India (FEDAI) and the Reserve Bank of India. Contract size (lot size): USD 1,000 per contract lot. A single lot of USD/INR options represents the right to buy (call) or sell (put) USD 1,000 at the specified strike price (expressed in rupees). Premium quotation: in Indian rupees per US dollar (e.g., premium of Rs 0.65 per USD = Rs 0.65 x 1,000 = Rs 650 total premium per lot). Tick size (minimum price movement): Rs 0.0025 per USD = Rs 2.50 per lot minimum P&L movement.
Strike prices: available in Rs 0.25 increments on the USD/INR rate (e.g., 83.00, 83.25, 83.50, 83.75, 84.00). Near the current rate, approximately 12 to 16 strikes are available on each side (call and put). Expiry: last working day of each contract month. If the last working day is a bank holiday, the expiry is the immediately preceding working day. Monthly series: typically 3 near months plus quarterly months are available simultaneously. Option style: European -- can only be exercised at expiry (no American-style early exercise, unlike Indian equity stock options). Settlement: cash settlement in Indian rupees at the RBI Reference Rate for USD/INR published on the expiry date at approximately 12:30 PM IST.
The RBI Reference Rate Settlement
The USD/INR options are cash-settled using the RBI Reference Rate published by the Reserve Bank of India on the expiry date. The RBI Reference Rate is the weighted average of market transactions in the interbank foreign exchange market during a specific window around 12:30 PM on the expiry date. This reference rate is not the same as the NSE market's last traded price -- it is an independent fixing based on the actual interbank transactions occurring simultaneously in India's banking system.
The settlement price (RBI Reference Rate) determines the final P&L for all expiring contracts: for a call option with strike 83.50 that expires when the RBI Reference Rate is 84.20: the call's intrinsic value = Rs 84.20 - Rs 83.50 = Rs 0.70 per USD. Cash settlement amount per lot = Rs 0.70 x 1,000 = Rs 700 received by the call buyer (deducted from the call seller). For a put option with strike 84.00 that expires when the RBI Reference Rate is 83.75: the put's intrinsic value = Rs 84.00 - Rs 83.75 = Rs 0.25 per USD. Cash settlement amount per lot = Rs 0.25 x 1,000 = Rs 250 received by the put buyer.
Margin Requirements for USD/INR Options
SEBI and NSE calculate margins for USD/INR options using a SPAN-based margin system similar to equity derivatives, with parameters calibrated to currency market volatility. Short option (sold call or put): requires SPAN margin plus an exposure margin. For a short USD/INR ATM call at current USD/INR of Rs 84.00: SPAN margin approximately Rs 1,500 to Rs 3,000 per lot (depending on VIX-equivalent currency volatility). Long option: requires only the premium paid -- no additional margin (maximum loss is the premium, already paid at entry). Credit spreads: margin benefit applies as in equity options -- the long protective option reduces the net margin required for the combined spread position.
USD/INR Option P&L Calculation Examples
Long 84.00 CE at Rs 0.55 premium. RBI Reference Rate at expiry: 84.85. Intrinsic value: Rs 84.85 - Rs 84.00 = Rs 0.85. Net gain: Rs 0.85 - Rs 0.55 = Rs 0.30 per USD. Per lot: Rs 0.30 x 1,000 = Rs 300 gain per lot. Short 83.50 PE at Rs 0.48 premium (sold). RBI Reference Rate at expiry: 83.10. Loss: Rs 83.50 - Rs 83.10 = Rs 0.40 intrinsic. Net P&L: Rs 0.48 received - Rs 0.40 loss = Rs 0.08 per USD gain. Per lot: Rs 0.08 x 1,000 = Rs 80 net gain per lot. Short PE expired with partial profit: seller keeps the Rs 0.40 difference between premium collected and intrinsic paid.
Multiple Currency Pairs - Beyond USD/INR
NSE offers currency options on four currency pairs in addition to USD/INR: EUR/INR (Euro vs Indian Rupee), GBP/INR (British Pound vs Rupee), JPY/INR (Japanese Yen vs Rupee), and cross-currency options (EUR/USD) for eligible participants. The specifications for these additional pairs differ from USD/INR in lot size (EUR/INR: EUR 1,000 per lot; GBP/INR: GBP 1,000 per lot; JPY/INR: JPY 1,00,000 per lot). The liquidity in these non-dollar pairs is significantly lower than USD/INR -- many strikes have thin or zero volume, making execution at fair prices challenging. For most retail traders: USD/INR options provide sufficient currency exposure and should be the primary focus before attempting the less-liquid non-dollar pairs.
The contract specification is the foundation on which every currency options calculation rests. An error in the lot size assumption (using 100 instead of 1,000) produces a 10x error in the hedge ratio. An error in the premium quotation (misreading Rs 0.55 as Rs 55) produces an entry at the wrong price level. Mastering the specification details before placing any currency options trade prevents these avoidable errors -- which are more common in currency markets (where the conventions are different from equity markets) than in equity options trading.
USD/INR Settlement Uses RBI Rate, Not NSE Market Price
A critical practical difference from equity options: USD/INR options settle at the RBI Reference Rate published at approximately 12:30 PM on expiry day, not at the NSE market's closing price. This means: (1) The options market may trade at a different USD/INR rate from the RBI Reference Rate during the final hours before expiry. (2) An option that appears to be ITM based on the NSE market price at 3:00 PM may actually settle OTM if the RBI Reference Rate was lower at 12:30 PM. Always monitor the RBI Reference Rate announcement on expiry day, not just the NSE market price, when managing positions approaching settlement.