Pharma:
"I'm curious what you see is keeping the shorts in at this point."
Shorts sell or hold depend on catalysts stimulating enough hope for longs to hold or even buy more. They realize that as time passes, the longs get impatient and sell. If the catalysts fail to live up to their promise, the shorts sell even more. If one or more of the lesser catalysts succeed, the shorts tend to hold. When cash starts coming through the door, the game is over and they cover.