Executive resignations, poor results, cavalier tone, and insider trading during the turmoil raise an inference of scienter, but not a strong one, and therefore do not state a claim.
http://www2.ca3.uscourts.gov/opinarch/172200p.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.