Extreme Loss Margin (ELM)
Extreme Loss Margin, abbreviated as ELM, is an additional margin charged by Indian exchanges to absorb losses from extreme price movements that the regular VAR or SPAN scenarios may not capture. It is layered on top of VAR for cash equity and on top of SPAN for derivatives. ELM is small compared to other components, but it kicks in heavily for volatile or low-quality scrips.
Key takeaways:
- ELM is an exchange-prescribed buffer for tail-risk scenarios.
- Typically 1.5%–5% on most stocks; significantly higher for scrips on surveillance.
- Added to VAR margin (cash equity) or SPAN + Exposure (derivatives).
- Aimed at protecting the clearing corporation when prices gap beyond standard models.
- Revised periodically; surveillance measures (ASM/GSM) can multiply ELM overnight.
Why ELM exists
Statistical risk models like VAR and SPAN assume that returns follow a known distribution and that the market moves smoothly enough to estimate scenarios. Real markets have fat tails — extreme moves happen more often than statistics suggest. ELM is the exchange’s acknowledgement that no model fully captures crisis behaviour. By holding ELM, the clearing corporation has extra capital to settle trades even when models break down.
Typical ELM levels
| Category | Indicative ELM |
|---|---|
| Nifty 50 / Index F&O | ~1.5–2% |
| Stock F&O | ~3–5% |
| Cash equity (regular) | ~3.5–5% |
| ASM Stage 1 stocks | +50% incremental ELM |
| ASM Stage 4 / GSM stocks | Can exceed 25% |
Interplay with VAR and SPAN
For cash equity intraday: Margin = VAR + ELM + Ad-hoc. For F&O: Margin = SPAN + Exposure + (ELM where applicable). The naming convention is slightly different across segments but the principle is the same — ELM rides on top of the risk-based margin.
ELM and surveillance
SEBI and the exchanges use ASM (Additional Surveillance Measures) and GSM (Graded Surveillance Measures) to flag stocks behaving unusually — for example, a small-cap that has rallied 50% in a month. When a stock enters ASM/GSM, ELM is raised sharply. The result: leverage on that stock collapses, often making active trading impractical. Traders should pay attention to ASM/GSM updates published nightly by the exchanges.
What this means for retail traders
- If your favourite stock suddenly needs much more margin than yesterday, check the ASM/GSM list — ELM has likely spiked.
- For F&O positions, watch for stocks just entering surveillance — your margin requirement can jump overnight.
- Long-term investors are unaffected operationally but can use ELM moves as a contrarian signal of speculative excess.
ELM caps and reviews
Exchanges review ELM at least weekly and can change it any business day. Reviews look at realised volatility, news flow, surveillance status and liquidity. Some commodity contracts have additional “ad-hoc” margins layered on extreme days that effectively work like a surcharge on ELM.
Frequently asked questions
Is ELM the same as exposure margin?
No. Exposure margin is a flat percentage on all positions; ELM is risk-tier specific and tied to surveillance.
Does ELM apply to mutual funds?
No. ELM applies to exchange-traded margin obligations only.
Can ELM be paid via pledged shares?
Yes, subject to the 50% cash rule.
How is ELM information available?
NSE and BSE publish daily risk parameter files containing VAR, ELM and ad-hoc margins for every scrip.
