ABSTRACT: Pseudonymous attacks on public companies are followed by stock price declines and sharp
reversals. These patterns are likely driven by manipulative stock options trading by
pseudonymous authors. Among 1,720 pseudonymous attacks on mid- and large-cap rms
from 2010-2017, I identify over $20.1 billion of mispricing. Reputation theory suggests these
reversals persist because pseudonymity allows manipulators to switch identities without ac-
countability. Stylometric analysis shows pseudonymous authors exploit the perception that
they are trustworthy, only to switch identities after losing credibility with the market.
PDF (81 Pages): Paper Mitts Short and Distort
