When a margin agreement is fully enforced, the maximum credit exposure is limited to the margin threshold plus the VaR over the Margin Period of Risk (MPoR).

Given:

• Initial value of contract ($V$) = 10,000 bags * $500/bag = $5,000,000
• Margin threshold = $500,000
• Margin period of risk = 2 days
• Annual standard deviation ($\sigma_{annual}$) = 25% = 0.25
• Number of trading days in a year = 252

First, calculate the 2-day standard deviation ($\sigma_{2-day}$): $\sigma_{2-day} = \sigma_{annual} \times \sqrt{\frac{2}{252}}$ $\sigma_{2-day} = 0.25 \times \sqrt{0.0079365} = 0.25 \times 0.089087 = 0.0222718$ (or 2.227%)

Next, calculate the 95% VaR over the 2-day margin period. The Z-score for 95% confidence is 1.645: 2-day 95% VaR = $V \times \sigma_{2-day} \times 1.645`$2-day 95% VaR = $5`,000,000 \times 0.0222718 \times 1.645 = `$183`,185

The total 95% credit Value at Risk given the margin agreement is: Credit VaR = Margin Threshold + 2-day 95% VaR Credit VaR = $500,000 + $183,185 = $683,185 \approx $683,200.