Greatly appreciated if someone would help me with the formula for the
following:

Using a stock price, for example, how do I can a cell automatically
calculate "cells" and not a time frame?

For example, I have the present formula:

=SUMIF(A50:A5000,TODAY(),F50:F5000)

This returns today's closing price on a summary page. But how do I get
it to automatically calcualte the today's closing price vs. 25 cells
ago (not time, but cells)? I can figure out how to calculate the above
minus the price of 25 days ago, but not 25 cells ago...

Thanks in advance,
E