"carla" wrote in message
...
I'm still learning excel... can you help me create a formula that
calculates
the difference (YTD gain/loss) for a range of amounts (monthly balances).

Suppose your opening balance is in A1 and your month end balances are in
A2:A13.
In B2, put this formula:
=A2-$A$1
Copy this formula down into B3:B13.
That will give you the YTD gain/loss.