I think I would jam the rest of my stack in there, can’t see a lot of hands that top 2 isn’t ahead of. Maybe he has a set of 9’s or 5’s, but there is little you can do about that. you beat AK, AA, KQ, K9 and all those sort of combinations. you also block hands like JJ and KK, so the hands that have you beat that are in his range and you don’t block are pocket 5’s, pocket 9’s and maybe a Q10 suited I guess, not sure if CO should open that hand tough. Depending on skill level of the player you can rule that one out as well. My guess is he either picked up some Ax kind of flush draw + straight draw (A10 or even AQ) or he might be protecting AK or AA or something from the flush draw.I can’t really be sure about his holding since I don’t know if he is loose pre flop, or tight, or…
anyway, against a random opponent I would jam all-in, you can’t call and leave yourself behind with a 1/4 pot sized bet behind and you can’t fold with top 2 on this board in my opinion.
how did the hand played out?