"While there may be other explanations for this phenomena, Occam's law would lead one in the direction of selective disclosure and trading upon material non-public information. Not that one should be surprised at this. The sheer number of people with privileged information is vast as is the trade in such information via "expert networks", even before considering friends, family, old boys' networks or similar networks of obligation and opportunity.exchange.
"Some think, and argue persuasively that Porsche is well-guilty of outright fraud."