As proposed here:
https://lweb.cfa.harvard.edu/~loeb/Juno.pdf
This market resolves Yes if Juno performs any intentional orbital manoeuvre or thruster burn with the explicit purpose of allowing a closer observation of 3I/ATLAS, such that Juno is closer to 3I/ATLAS than it otherwise would have been.
If Juno observes 3I/ATLAS but has remained in its planned orbit, then this resolves No. If manoeuvres are attempted but fail, or communications failures prevent us from knowing whether they succeeded, this resolves No.
No + Avi Loeb is literally retarded. Juno does not have enough ΔV to do those maneuvers and its primary thruster stopped working: https://www.space.com/space-exploration/missions/nasas-juno-probe-orbiting-jupiter-may-have-come-to-an-end-but-no-one-can-confirm