For all the talk about the importance of stare decisis during John Roberts' confirmation hearings, the Roberts Court hasn't been shy about making bold changes to existing precedents in at least one area of the law–antitrust.

The Court kicked off the year by setting a stringent new standard for plaintiffs to prove predatory buying in Weyerhaeuser v. Ross-Simmons Hardwood Lumber.

The Court ruled that a plaintiff that alleges anticompetitive activity on the supply side must prove both that the defendant's activity led to below-cost sales and that the defendant was likely to later recoup those losses by squeezing out competitors and then raising its prices.