A stream has a baseline but then there are huge and very regular waves above that baseline as bots are added periodically added and YT subsequently removes them. When the bots are deactivated the stream immediately returns to the baseline. I speculate that the bot companies promise a certain CCV level or range and push in more bots regularly to keep the stream in the range promised.
A single shot bot buy has this massive ramp up and fall off that is also pretty obvious.
Of course it could be that different companies and sources of bots exhibit different viewership patterns so this is all based on what we've seen lately on the EN side.
Good example, you can see the baseline and also where a shit ton of bots both piled in and then subsequently piled out:
You can have natural wave patterns too but those are pretty obvious if matched to events of the stream. For example Apex streams will have a peak and fall at the end of rounds very consistently. Games with timed rounds sometimes exhibit a bot-like wave pattern as the spacing is dead even like bots are. There's also YT error spikes (jp calls this an N pattern and en numberfriends call it a Z) which are usually to do with unstable servers or connections but often seem completely random.