Regulatory guidelines mandate an additional 2% Extreme Loss Margin (ELM) on sold index option contracts on expiry day. 

Applies to all positions, intraday or overnight. 

Example: Nifty 25000 CE ~?12,500/lot. 

Margins apply from Expiry Day -1; shortfall may lead to square-off during the first hour of expiry day trading. 

Check Order Window for margins & Funds Menu for utilization. Ensure sufficient funds to avoid square-offs. 

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