any sane short is only in the immediate short-term for a quick buck. personally, i think today's move was ridiculous and unsustainable. that doesn't mean it doesn't head higher in a few days or week. i just think it'll give up a few percent before (and if) it continues its run. and i'll cash out.
if i had money freed up a few days ago i would have been a buyer. i'm really quite annoyed i missed out on Tesla and SCTY the last 10%. But I've made a lot on Facebook so I'm quite happy. And honestly I couldn't comfortably put as much on these stocks as i would in Facebook. i find Tesla and Solarcity much more risky positions.