How an iPhone announcement affects Apple’s share price by Philip Elmer-DeWitt @FortuneMagazine September 3, 2012, 11:02 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Source: Mashable. Click to enlarge. FORTUNE — Last March, Mashable‘s Matt Silverman, with help from Statista, produced a series of charts showing what has happened historically to Apple’s AAPL share price in the five days before and after a product announcement. The general pattern, represented by the small chart above left, was a variation on the old adage “buy the rumor, sell the news.” The exception, shown in the large chart at right, was the iPhone. As of Labor Day, Apple had not sent out any press invitations, but if the rumors are to be believed, the company will unveil the newest edition of the iPhone on September 12, seven trading days from Monday. Just saying.