When do derivative shareholder claims survive a corporate merger? That was the important question that the Delaware Supreme Court considered Wednesday during oral arguments in a case arising from Bank of America's acquisition of Countrywide Financial Corporation in 2008.

A Florida woman who claims that she was injured by Teva's generic version of a brand drug manufactured by Wyeth and Schwarz Pharma can't sue any of the companies, an Eleventh Circuit panel ruled on Tuesday. The panel found that the woman's claims against Teva were barred by a U.S. Supreme Court ruling, and that her claims against Wyeth and Schwarz were barred by Florida law.

Bank of America may have thought it put its mortgage robo-signing woes behind it with the government's $25 billion foreclosure settlement. But the bank could be far from clear of securities claims over the scandal, thanks to a little-noticed ruling last Friday allowing a mortgage-backed securities investor to press allegations over suspect mortgage documents.