You can monitor fundraising at the FEC website: https://www.fec.gov/data/browse-data/

Some PACs file quarterly and some monthly. I think it depends on size & volume. So this site won’t ever have up to the minute data, but you can search out individual contributors. I used to compile filings for my employer’s PAC. It was a tiny PAC comparatively, and it swung one way or the other depending on which candidates were in favor of the PAC’s main issue. But learning the internal machinations was eye opening.

He’d tell you about it non-stop if he was.