A Practice Note discussing provisions used in purchase or merger agreements to allocate antitrust risk, known as antitrust risk-shifting provisions. This Note provides an overview of the most common types of risk-shifting provisions, including antitrust cooperation provisions, divestiture and litigation obligations, antitrust filing fee allocation, and reverse break-up fees. This Note discusses when counsel should include these provisions in an agreement and other considerations. It also provides links to standard risk-shifting provision language that may be inserted into agreements as well as sample provisions from transactions in the What's Market Antitrust Risk-Shifting Database.