margins are at their lowest four days before expiration and gradually increase each day until the expiration day. Here’s how it progresses:

• Four days before expiration: 10% of the calculated delivery margin
• Three days before expiration: 25% of the calculated delivery margin
• Two days before expiration: 45% of the calculated delivery margin
• One day before expiration: 70% of the calculated delivery margin
• On expiration day: 100% of the calculated delivery margin

The calculated delivery margin includes VaR (Value at Risk), ELM (Extreme Loss Margin), and any ad hoc margin:

• VaR measures potential trader losses at a specified confidence level and time horizon. 
• ELM provides an extra margin for unforeseen losses beyond VaR. 
• Ad hoc margins are temporary measures applied by exchanges or brokers to address specific market conditions or risks not covered by regular margin requirements, particularly during periods of high volatility or uncertainty.