In 1995, Congress passed the Private Securities Litigation Reform Act (PSLRA), which dramatically heightened the pleading burden for plaintiffs bringing securities fraud cases. At the same time, the PSLRA also instituted a mandatory stay on discovery until resolution of any motions to dismiss, which means plaintiffs have to use their own investigation – relying on public information, confidential sources, and the like – to draft a complaint that is sufficiently particular to satisfy PSLRA standards.
In 2002, Steve Bainbridge and Mitu Gulati published How Do Judges Maximize? (The Same Way Everybody Else Does – Boundedly): Rules of Thumb in Securities Fraud Opinions. The paper explained that, given the high pleading standards of the PSLRA, judges deciding motions to dismiss lighten the workload by coming up with various rules of thumb for determining whether a complaint pleads materiality or scienter. For example, they identified the puffery doctrine (presuming that investors treat vague statements of optimism as immaterial), the bespeaks caution doctrine (predictions of the future are immaterial if they are caveated by warnings of future uncertainty), and fraud by hindsight (refusing to draw inferences about what the company knew at an earlier time due to negative disclosures at a later time)