My guess is what is driving the shorts is the recent massive price jump on the back of only a small amount of new information from the company. It's not a crazy view to think NEA isn't worth $600M (yet), and there is a reasonable probability that the share price will fall from its current historic highs (before rising again). Over the next few weeks, given the current price of $1.55, would it be fair to say it's more likely to fall to $1.20 than it is to rise to $1.85? I'd say it's 70%/30%.
Also, why do the shorts seem "very short term"? How can you tell the intended holding period of a short?
NEA Price at posting:
$1.55 Sentiment: Buy Disclosure: Held