Source: Flickr user Karlis Dambrans. 

What: Shares of technology giant Apple (NASDAQ:AAPL) inched higher by $0.79 in trading on Monday to close at $119.72, just shy of a $700 billion valuation, after research firm Canaccord Genuity upped its price target on Apple's stock.

So what: According to Canaccord Genuity's analyst Mike Walkley, who maintains a "buy" rating on Apple, consumer upgrades to the new iPhone 6 and its larger iPhone 6 Plus size, as well as steady long-term replacement sales, should push Apple to steady growth and the opportunity to sell 210 million to 215 million iPhone units annually between 2015 and 2018.

Specifically, Walkley notes that his analysis of market trends suggests that Apple captured 93% of smartphone profits in the fourth-quarter, with a majority of its peers running in the red. By 2018, Walkley forecasts that Apple could hold a third of all premium smartphone subscribers, or an estimated 650 million out of a projected 1.82 billion global smartphone users.

Given its brightening prospects Walkley and his firm raised their price target on Apple $10 to $145, implying 21% upside based on Monday's closing price. 

Source: Flickr user Jeyulio_.

Now what: The question that investors need to be asking themselves here is whether or not Apple is really worth $145 per share, or nearly $850 billion.

On one side of the coin we have a long history of outperformance at Apple and a clear indication that it's deserving of the title, "most valuable company in the world." In its recently reported holiday quarter Apple sold 74.5 million iPhones and reported an $18 billion profit, the highest quarterly profit ever reported by a public company. Tack this onto its latest innovations such as the iWatch and Apple Pay and there are plenty of reasons for investors to believe Apple could head higher.

But, Apple's greatest weakness may also be borne from its incredible innovative success. I suspect the biggest threat to a $145 price target would be its products getting too efficient and ahead of the curve. In plainer terms, Apple needs to offer products with new features to excite consumers, but not so many improvements that consumers skip the next upgrade cycle and hold onto their mobile devices for three, four, or five years. I know that may sound like an eternity now, but these devices are being built to last longer, and it's a genuine concern.

So, returning to our original question: Is Apple worth $145? Taking into account Apple's enormous $178 billion in cash (which is mostly overseas), the incredibly brand-loyalty that its products inspire, and its encouraging earnings data, as well as the replacement cycle risk, I see no reason why $145 couldn't be supported at some point in the future.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.