I've been interested in adding Optimism and ImmutableX to my portfolio but their price has been inflated after big run ups.

Now they are both in freefall and I'm considering an entry point.

How do you decide where to take the plunge?  A certain %drop from the top or a %above bottom?

Or do you just look at previous levels as the traders always mention, Optimism is getting close to some previous tops at $1.3 for example?

Or do you get buy targets from another source?