The traditional origin is said to be a curse set upon the play by a coven of witches, angry at Shakespeare for using a real spell.[2] One hypothesis for the origin of this superstition is that Macbeth, being a popular play, was commonly put on by theatres in financial trouble, or that the high production costs of Macbeth put theatres in financial trouble, and hence an association was made between a production of Macbeth and theatres going out of business.[3]