show total in a grid of all pages

Have you tried the dashboard option?
You can put a total panel and a grid panel.
Regards,
fernando

Put a snippet on your list page and in this snippet query for the total with DB::Query and echo the result.

https://asprunner.com/forums/topic/21091-implementing-running-total-in-phprunner/
... for inspiration purposes only ...

What I've done for accounting/money tracking was to create a separate column for the balance. Whenever a new deposit/withdraw is done, I read the last balance, add/subtract from that, and set that as the new balance on that row for that transaction. I've prevented editing the deposit/withdraw amounts, as to not taint the log with the ability to change data. If a correction is needed, a new entry must be made.

I would also suggest using a code snippet for this purpose and calculating grand totals manually.

Thanks !