The body language from the U.S. Supreme Court justices in last week's oral arguments in the Matrixx case suggest drug and device companies will have to disclose more information about adverse events. How much more will depend on where the justices draw the line.

Matrixx Initiatives Inc. et al. v. James Siracusano et al. was originally meant to determine whether investors can claim securities fraud when a pharmaceutical company does not disclose adverse events that are not statistically significant. Once it became apparent at the oral arguments that the answer to that question is a qualified "yes," the justices began to focus on what level of information about non-significant AEs might be material to investors.