Haha, that was me that posted the short interest is non-existent. As for shorting it as retail I called my broker to find out exactly the requirements and they told me that it is a case by case basis on the requirements to short. So I asked theoretically about AMBS and $25,000 in margin would be enough to short it.

As for the people who are shorting it, they are shorting/covering same day so there is no short interest accumulation. Not to mention, those very people arb'ing may already have a core position in the case of a fire. (Massive run up) so yes, they would have to sacrifice shares they own, but would not be underwater. It would have been actually very clever to do the last few months to make some money, but since new info is eminent, not so much now.

With the spread so big all you would have to do is short say 50,000 shares at .0805 today at open, sit on your hands for a bit and wait for the spread to widen, and then place your buy orders at the bid at .077. That is 4.5% and with commissions both ends, the profit would be about $159.10. Is it worth the risk for $159.10 to me? It wouldn't be worth that type of risk to me for $1591.00. But some people deem that $159.10 is worth playing with fire. To each their own.