A FTD stands for Failure To Deliver and is initiated when stock is sold naked, and is still not delivered after a number of days (meaning that the buyer of stock has effectively purchased counterfeit stock).

This is usually rectified simply by the stock being provided, and in the case of a regular investor, an FTD may result in his broker purchasing stock back from the market to cover the FTD, although in the case of larger businesses they may engage in causing a strategic FTD as part of an illegal naked short strategy.