Divergent market expectations and positive consumer reviews of the new iPhone have made Apple an increasingly controversial stock, CNBC's Jim Cramer said, but if demand for the new smartphone outpaces expectations, it could be a turning point.
"I've been puzzled over Apple," Cramer said on "Squawk on the Street" Wednesday. "I think the stock is very, very cheap. This could be a catalyst. We're starting to hear good things about demand. It will move the needle if they sell out."
Cramer said that personally, he was expecting to buy a new version of the iPhone, "These reviews are extraordinary, so you just go buy it."
Opinions of Apple had been dampened recently, after the company didn't announce a major deal to expand into China and many analysts worried about "sticker shock" in the country over the iPhone 5C. However, he said that reviews of the device and software could reinvigorate both analyst and consumer enthusiasm.
As a result, Cramer said that "this has got to be the single most controversial stock I've ever seen in my career. You love the product … why isn't the Apple love there? The answer is because the institutions don't care for Apple anymore."
Much-loved stocks like Tesla, Netflix and Amazon are beneficiaries of the high regard from markets and as a result are relatively disconnected from the P/E multiple expectations you'd see for most companies, Cramer said. There is no "Apple metric" to set it apart from the pack, he said.
Cramer explained that for Apple, institutional investors are looking for a new product that will shake up markets and are concerned with year-over-year growth.
However, he said that Apple is a "big value stock" and right now "it's very cheap." On top of the positive reviews from industry watchers, he pointed out that Morgan Stanley and Pacific Crest recently put out positive investor notes on the company, after last week's announcements and better-than-expected demand.
Cramer suggested that investors key off shipping information from UPS on Apple products, which in the past has been a useful early sign of demand.
"The stock has been a very tough stock to own, but you need to see positive momentum in earnings and you need to see a new product," he added. "These reviews read like it is a new product."
Jim Cramer's charitable trust owns shares of Apple.
—By CNBC's Paul Toscano. Follow him on Twitter @ToscanoPaul and get the latest stories from "Squawk on the Street."