Maintenance Margin
Abroad, the exchange lets your deposit drift down to a floor before it calls. On NSE the floor is the full margin, every day, which is why the call comes sooner than newcomers expect.
In short: maintenance margin is the level below which a margined account must not fall after the daily mark to market; breaching it triggers a demand to top up to the initial margin. The term comes from markets such as CME where the maintenance level is set below the initial level. On NSE there is no separate lower level: the full SPAN plus exposure requirement must be maintained daily, so in practice the maintenance margin and the initial margin are the same number, and brokers add their own earlier warning thresholds.
The intuition
Imagine a deposit that is topped up only when it gets low. You put in the initial margin on day one. Daily losses are taken from it. The exchange does not want to bother you for every small dip, so it sets a floor, the maintenance margin, some way below the initial level; only when the deposit drops through that floor does it demand that you bring the balance back up to the initial margin. That is the two-level system used by US futures exchanges, and it is the one most textbooks describe.
Indian exchanges chose a one-level system. The requirement is the full initial margin, recomputed each day, and the account must meet it at every daily check. A loss that leaves the balance below today’s requirement is a shortfall at once. There is no grace band. The practical consequence is that the buffer the US system builds into the rules has to be built by the trader instead, by funding above the requirement.
Formula
Two-level system (CME-style): call is made when account equity < maintenance margin; top-up required = initial margin − account equity
NSE: call is made when available margin < SPAN + exposure margin (recomputed daily); shortfall = requirement − available margin
Available margin = cash + collateral value after haircut − margin blocked on other positions ± settled MTM.
Worked example (illustrative numbers)
Suppose NIFTY is at 24,000 and a trader holds one long lot (65 units) of futures with an initial margin requirement of ₹1,71,600 and exactly ₹1,90,000 in the account, a buffer of ₹18,400.
| Day | Settlement | MTM per lot | Balance | Requirement | Status |
|---|---|---|---|---|---|
| 1 | 23,900 | −₹6,500 | ₹1,83,500 | ₹1,71,000 | OK, buffer ₹12,500 |
| 2 | 23,700 | −₹13,000 | ₹1,70,500 | ₹1,74,000 (IV up) | Shortfall ₹3,500: call |
| 3 | 23,650 | −₹3,250 | ₹1,67,250 | ₹1,74,000 | Shortfall ₹6,750: square-off risk |
Under a US-style rule with maintenance set at, say, 75% of initial, the floor would have been about ₹1,28,700 and no call would have been made by day 3. On NSE the call comes on day 2, after a 1.25% fall, because the requirement is the full margin and it rose at the same time the balance fell. The requirement moving up while the balance moves down is the normal pattern in a sell-off.
Why it matters to an options trader
- Short option margins behave the same way. A written straddle or strangle is held to its full recomputed requirement daily; a rise in implied volatility alone can create a shortfall without any price move.
- The buffer is your job. Writers who fund the exact requirement are, in effect, running at the maintenance level from day one.
- Brokers add earlier triggers. Most Indian brokers’ risk systems warn or square off when the shortfall reaches a set percentage of the requirement, often before the exchange’s own penalty applies; the broker’s policy page is the operative rule.
- Profits help immediately. MTM gains credited to the ledger count toward the requirement the next morning, so a winning position builds its own buffer.
Common mistakes
- Importing the US rule. Expecting a 25% grace band that does not exist on NSE.
- Watching price but not the requirement. The requirement moves; a shortfall can appear on a flat day when the SPAN file widens.
- Relying on pledged collateral alone. Haircuts rise on volatile days and a fall in the pledged stock cuts collateral value exactly when the futures lose money.
- Assuming the broker will wait. Square-off rights are in the account agreement and are used on sharp days.
Indian-market specifics
- NSE Clearing requires initial margin (SPAN plus exposure) to be maintained in full at each daily computation; there is no separately published maintenance level. Daily MTM on futures is settled in cash on T+1 (NSE equity derivatives settlement mechanism).
- Under SEBI’s peak-margin framework (July 2020 circular, 100% from 1 September 2021), the requirement is verified against the beginning-of-day margin parameters; a short collection attracts a penalty on the broker under SEBI’s 2011 circular on penalties for short-collection of margins, which brokers pass on to clients.
- Brokers publish their own risk-management thresholds for warnings and square-offs; these are contractual and vary, and are the number that actually triggers a call in practice.
- The term maintenance margin also appears in SEBI’s margin trading facility rules for leveraged cash-market purchases, a different product with its own levels.
FAQ
Is there a maintenance margin on NSE?
No separate level; the full initial margin must be held daily.
What is the difference between initial margin and maintenance margin?
Initial opens the trade; maintenance is the floor for a call, and in India they coincide.
What happens if my balance falls below the requirement?
Top up or face square-off and a shortfall penalty.
Does maintenance margin apply to option buyers?
No; only futures and short options.
Watch the requirement, not just the price
The futures margin calculator estimates the full daily requirement for a Nifty or stock futures lot. In the app, the Option Chain page shows implied volatility by strike, the input that widens the SPAN requirement on stressed days.
Related terms
- Initial Margin, the level NSE enforces daily
- Margin Call, what the breach triggers
- Mark to Market, the daily debit that erodes the balance
- Peak Margin, the upfront-collection rule