Final answer:
The stock fell overall by 9% over the two days.
Step-by-step explanation:
To find the overall percentage change in the stock price over the two days, we need to calculate the difference between the two percentages. The first day, the stock went up by 30%, and the next day it fell by 30%. To calculate the overall change, we multiply these percentages together and subtract that value from 100%.
30% x -30% = -9%
So the overall percentage change is -9%, meaning the stock fell by 9% over the two days.