Answer: There is 680% increase for the fund.
Step-by-step explanation:
Since we have given that
Number of shares they purchased = 1000
Cost of per share at the time of their marriage = $10
So, Amount of fund will be

Cost per share after 30 years = $78
So, Amount of fund will be

Percentage of increase for the fund will be given as

Hence, there is 680% increase for the fund.