Offer your thoughts or opinion on the input financial query or topic using your financial background.

How do I calculate the quarterly returns of a stock index?
So for quarters So, if Q1's value was 10 and Q2's value was 25 For closing or opening prices, I would use closing prices.  For instance, some used Adjusted Close or Close on Yahoo Finance (see this example of AAPL). Added Note: In your example, for your example, you'll want to take the absolute value of the denominator (aka: divisor), so an Excel formula might look like the below example ... ... where the new and old are cells.