Final answer:
The value of the portfolio is expected to increase by approximately $2,031,250 if all yields increase by 25 basis points.
Step-by-step explanation:
The modified duration of a bond portfolio measures the sensitivity of the portfolio's value to changes in interest rates. In this case, the modified duration of the bond portfolio is given as 4.625 years. A basis point is equivalent to 0.01%, so a 25 basis point increase is equivalent to a 0.25% increase in interest rates. To calculate the approximate change in the value of the portfolio, you can use the formula:
Change in portfolio value = (Modified duration) x (Change in interest rates) x (Current value of the portfolio)
Plugging in the given values, we get:
Change in portfolio value = 4.625 x 0.0025 x $175 million
Change in portfolio value = $2,031,250
Therefore, the value of the portfolio is expected to increase by approximately $2,031,250 if all yields increase by 25 basis points.