Plaintiff need not sell stock to establish loss causation for standing -- purchase at inflated price and holding at reduced value suffices for particular injury.
Where there was no alternative that would have avoided the fall in stock price, the allegedly harmful timing of the disclosure might have been a legitimate business decision. ANy hedging strategy would, as a matter of law, have required disclosure. Additionally, the board could no have been certain that the employee stock plan would be a net purchaser during the period under consideration.
http://www.ca5.uscourts.gov/opinions/pub/17/17-50702-CV0.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.