[Alas Babylon!]

... for almost 9 months after he took office ...

I think they started 9 months BEFORE he took office. The FISA warrant on Page was from 2016.

[kabar]

Correct. The Carter Page warrant was extended twice. They spied on Trump's campaign, his transition, and as President. I find the spying on him as President for 9 months as the most egregious.

They started the spying officially on October 15 when the primary warrant was issued. It was requested on October 1. IMO they were spying on Trump well before that.