Apple CEO Tim Cook speaks about the new iPhone products during the announcement.

When it comes to Apple products announcements, the strategy of "buy the rumor, sell the news" has worked more often than not.

Of the last 10 times Apple has held a special event to unveil a new product, its shares finished the day lower after six of those events, for an average decline of 1.3 percent. The stock fell 2.3 percent Tuesday and was trading lower in premarket trade on Wednesday. (Click here to track its share price.)