Apple investors are now suffering from an unusual condition: loss of money.

After surging as much as 42 percent from the end of 2016 to the beginning of September, Apple has seen a bracing series of losses. The stock slid 5 percent last week alone, for its worst weekly performance in more than a year.

Recent concerns have revolved around Apple's new iPhone 8 and iPhone X products, which were unveiled on Sept. 12. Mild reviews for the iPhone 8 and talk of short lines for the product appear to have taken some wind out of the stock's sails.

Yet Wall Street analysts, always a group somewhat predisposed toward looking on the bright side, say the lack of enthusiasm could actually be a bullish indicator.

"Any Weakness for Early Sales of iPhone 8 Could Be a Case of 'Short-term Pain for Long-Term Gain,'" Piper Jaffray analyst Michael Olson advised in a Friday note. He explained that "potential buyers may wait for iPhone X," and that since the X will tend to be about $250 more expensive than the 8, "a mix shift toward iPhone X, even to the detriment of near-term iPhone 8 units, is positive for Apple."