I think in hindsight I would have called the turn to keep bluffs in but my time bank ran out. I figure he 4-bets AK pre and folds most of the low pairs/low a-x's so the only hand that makes sense here is possibly a5s (2 combos) and 55 (3 combos)? This raise just doesn't make any sense to me. I guess some of the time we are chopping with the same hand and he's just fast playing the turn or it's a weirdly played AK. Occasional AJ/A10 that is just overplaying and probably a fair amount of bluffs that just floated A dry.