The « subprime » financial crisis in the U.S. jeopardized many M&A contracts through the use of « reverse break-up fee » clauses as well as « Material Adverse Change” clauses: these clauses have been triggered by purchasers intent on freeing themselves of onerous obligations by arguing that the condition of the targets had deteriorated. The article analyzes the mechanics of these clauses and the manner in which they affect strategic and financial investors who invoke them. The article concludes that, under pressure from banks that used to finance the deals made by private equity funds, the use of these clauses increasingly transforms M&A contracts into mere purchase options.