That's a useful number to be sure, but another useful number is what size of move you're actually betting on with your position. Even with no IV contraction, an up move toward a long straddle loses money before it makes money. You were betting on a couple points or more down, or so far up that it overshot your straddle by a week and a half. So, a pretty significant directional bias. If you'd opened a 70 straddle, about the same moneyness (thus about the same price) but with opposite directional bias, that puppy would be worth 9 intrinsic now.
I guess that all of this means that even with Straddles you need to have a bias towards one direction.
No, not necessarily, it just needs to be ATM. In this case, I guess the 70/75 strangle would've worked better.
When I used to trade long straddles, I would simply buy more on the weak side (or buy fewer on the strong side ) if I wanted neutrality. I'm curious as to how your straddle would have fared had you neutralzed it this way. IV contraction vs. a slightly favorable move. My guess is that it would have been near breakeven.