The biggest consumer technology product event of the year will be held Tuesday.

Wall Street firms are giddy with optimism, predicting Apple will unveil the most innovative iPhone in years during the Sept. 12 session.

"We remain bullish on Apple and continue to be in the 'supercycle' camp on the next iPhone, as well as its ability to drive app sales. We expect the next iPhone to include innovations that will be clearly visible, marketable, and useful for the mass-market globally," Macquarie Research's Benjamin Schachter wrote in a note to clients Monday.

"We think that with expected innovations around AR [augmented reality], wireless charging, viewable screen size, OLED [display], and more, the next iPhone is clearly poised for its largest upgrade cycle yet."

The smartphone maker is one of the market's best-performing names so far this year. Its shares have rallied 39 percent year to date through Monday versus the S&P 500's 11 percent return.

"This year's September event is easily the most anticipated iPhone launch given expectations for the first major form factor change since the iPhone 6 cycle and excitement surrounding a host of revolutionary features/capabilities alongside evolutionary updates surrounding the flagship device," RBC Capital Markets' Amit Daryanani wrote in a note to clients Sunday. "Although expectations remain high, we think the event still has potential to surprise investors on the upside, particularly as some of the new iPhone features are demonstrated live."

Macquarie and RBC Capital Markets reiterated the firms' outperform ratings on Apple shares going into the event. Both research shops have $180 price targets for the stock, representing more than 11 percent upside to Monday's close.

One analyst emphasized any details on the high-end next-generation iPhone, widely expected to be named iPhone X, are a key factor for the event.

"At this point we see the risk to our earnings model as relatively small heading into the Apple event on Tuesday," JPMorgan's Rod Hall wrote Monday. "The main variable at this point is the specific week of availability for the OLED iPhone X in October though we continue to believe that Apple began volume production in September. The price is a smaller but also relevant variable."

Employing data from Kensho, a quantitative tool used by hedge funds, CNBC also ran a study to find out how Apple shares performed after iPhone announcement events since 2007.

The stock on average is roughly flat the day of the event, up 1.2 percent one week after the announcement and up 2.6 percent three months later, according to Kensho.



— CNBC's Michael Bloom contributed to this story.



Disclosure: NBCUniversal, parent of CNBC, is a minority investor in Kensho.



Correction: Apple is expected to unveil a new iPhone on Sept. 12. An earlier version misstated the date.

