How F&O SPAN Margin is Calculated
Learn how SPAN margin, exposure margin, and mark-to-market (MTM) work in NSE and BSE futures trading. Understand margin requirements, margin calls, and how to manage leverage responsibly in F&O trading.
Futures trading allows investors to take leveraged positions on stocks, indices, commodities, and currencies but this leverage comes with mandatory margin requirements set by the exchange and SEBI. Understanding how margin is calculated is not just important for compliance it is essential for managing risk and avoiding the dreaded margin call that can wipe out your trading capital.
What is Margin in Futures Trading?
In futures trading, margin is the amount of money you must deposit with your broker as collateral to take or hold a futures position. Unlike in cash equity trading where you pay the full price of the shares, in futures you only pay a fraction of the total contract value this is the core of leverage in derivatives.
For example, if a Nifty 50 futures contract has a total value of ₹10,00,000 and the margin requirement is 10%, you only need to deposit ₹1,00,000 to control ₹10 Lakhs worth of exposure. This gives you 10x leverage amplifying both gains and losses.
Types of Margin in Indian Futures Markets
1. SPAN Margin (Initial Margin)
SPAN stands for Standard Portfolio Analysis of Risk. It is a risk-based margining system used by NSE and BSE to calculate the minimum margin required to hold a futures position. SPAN margin is calculated by the exchange using a complex algorithm that considers:
- The current price of the futures contract
- The volatility of the underlying asset (typically based on historical and implied volatility)
- The time to expiry of the contract
- Potential worst-case loss scenarios across a range of price and volatility moves
SPAN margin is updated by the exchange six times a day during market hours, so your required margin can change intraday. Typically, SPAN margin ranges from 5% to 15% of the contract value for major indices and stocks.
2. Exposure Margin
In addition to SPAN margin, exchanges charge an Exposure Margin (also called Additional Margin) to cover residual risks not captured by SPAN. For NSE futures:
- Index futures (Nifty, Bank Nifty, Sensex): Exposure margin = 3% of the contract value
- Stock futures: Exposure margin = 5% of the contract value (or 1.5 times the Standard Deviation of daily returns, whichever is higher)
3. Total Margin (SPAN + Exposure)
The Total Initial Margin required to initiate a futures position is:
Total Margin = SPAN Margin + Exposure Margin
Futures Margin Calculation: Step-by-Step Example
Let's calculate the margin required to buy 1 lot of Nifty 50 Futures:
| Parameter | Value |
|---|---|
| Nifty Spot Price | 25,000 |
| Lot Size | 25 units |
| Contract Value | 25,000 × 25 = ₹6,25,000 |
| SPAN Margin (approx. 9%) | ₹6,25,000 × 9% = ₹56,250 |
| Exposure Margin (3%) | ₹6,25,000 × 3% = ₹18,750 |
| Total Margin Required | ₹75,000 |
To control ₹6.25 Lakh worth of Nifty exposure, you need approximately ₹75,000 in your trading account giving you roughly 8.3x leverage.
Mark-to-Market (MTM) Settlement
One of the most critical concepts in futures trading is Mark-to-Market (MTM) settlement. Unlike stocks, where unrealised losses stay on paper until you sell, futures positions are settled to market every day at the closing price.
- If the futures price moves in your favour, the profit is credited to your account the next morning.
- If the price moves against you, the MTM loss is debited from your account overnight.
- If your account balance falls below the maintenance margin level (typically 75% of initial margin), your broker will issue a margin call, requiring you to top up immediately or face forced liquidation.
Maintenance Margin vs Initial Margin
| Margin Type | Definition | Typical Level |
|---|---|---|
| Initial Margin | Amount required to open a position (SPAN + Exposure) | 8–15% of contract value |
| Maintenance Margin | Minimum balance to maintain a position without a margin call | ~75% of Initial Margin |
SEBI's Margin Rules: Peak Margin Reporting
Since August 2021, SEBI requires brokers to collect upfront margin from clients before allowing futures trades this is the Peak Margin Rule. Key points:
- You must have the full initial margin available in your account before placing the trade, not just at the end of the day.
- Brokers report peak margin utilisation to the exchange four times per day.
- Violations attract a penalty of 0.5% to 5% of the shortfall amount, charged to the client.
Practical Risk Management Tips for Futures Traders
- Never deploy 100% of capital as margin: Keep at least 30–40% of your trading capital as a buffer for MTM losses and margin calls. Running tight on margin leads to forced exits at the worst possible prices.
- Use Stop-Loss orders: Always place a stop-loss order when entering a futures position. Futures positions can lose more than the margin deposited if left unhedged.
- Understand the lot size: Each index and stock future has a fixed lot size. Nifty (25 units), Bank Nifty (15 units), and individual stocks have different multipliers always calculate your total contract value and margin before trading.
- Track margin changes before expiry: Exchanges increase margin requirements in the last week of expiry (called "expiry week margins") due to higher volatility. Plan your capital accordingly.
- Use our Futures Margin Calculator: Enter the futures contract, lot size, and current price to instantly see the exact SPAN + Exposure margin required, contract value, and leverage ratio.
"Margin is not a deposit it is a risk commitment. The trader who understands margin requirements, MTM mechanics, and leverage ratios before entering a futures position is the one who survives and thrives in derivatives markets."
Use our free Futures Margin Calculator to instantly compute the SPAN margin, exposure margin, and total margin required for any NSE or BSE futures contract. Also use our Brokerage Calculator to factor in transaction costs before evaluating the profitability of your futures trades.