[RearNakedChoke]

I think it's a clear fold. Large overbets like that tend to from huge hands. Some say "If he had a hand why would he bet so much?" The answer is to get paid off by a big hand, also with all of the calling stations at 100nl these plays can be 100% correct under the right circumstance. Overbets just aren't bluffs often enough to call here, and a bluff is all that you can beat.

*I say this assuming the player isn't a manic on tilt or super donk, as I figure you'd of mentioned that.