Image source: The Motley Fool.

The stunning four-day winning streak for Apple (AAPL 1.30%) stock came to an end on Friday, but that didn't stop one Wall Street pro from gushing about the investment's prospects. BMO Capital analyst Tim Long raised his price target on the stock from $116 to $140. He's keeping his bullish outperform rating, of course. 

He's encouraged by the commentary coming out of stateside carriers on initial iPhone sales, an important barometer because Apple itself has announced that it won't be offering opening weekend iPhone sales as it has in the past. A supply shortage -- particularly of the new jet black models and the larger iPhone 7 Plus -- will make it tricky to get an initial read on the iconic smartphone's early success. 

Carriers have been offering generous trade-in offers and discounts on iPhone products, making a big deal out of an update that many feared would just be a placeholder until Apple dramatically changes things in time for next year's update. Next year's model will mark 10 years on the market, and Apple isn't likely to squander that round milestone.

Long feels that iPhone sales will top expectations. He's also upbeat about the prospects for Apple Watch Series 2 in the coming quarters.

Hardware upgrade cycles will be lumpy. Apple investors know that all too well. They saw it rear its head when sales began to slip in the shadow of 2014's iPhone Plus rollout. However, Long feels that Apple's services revenue -- which he expects to grow at a 10% annualized clip through at least 2019 -- will provide more consistency to Apple's financial performance in the future.

The ride up to $140

Apple shares moved sharply higher in each of this past week's first four trading days, soaring 12.1% in the process. The stock took a 0.6% step back on Friday, but the trading still played out as a healthy 11.4% pop for the week. 

It's a surprising move in light of the 4.3% hit the stock took a week earlier when it actually unveiled the iPhone 7 and Apple Watch Series 2. The market wasn't initially impressed, but there's excitement now on Wall Street with some buzz building for the smartphone update and carriers are getting aggressive in trying to outfit customers with the pricey handsets. 

BMO Capital isn't the only firm moving up to $140 as a near-term stock goal. Canaccord analyst T. Michael Walkley also boosted his price target, going from $120 to $140. His survey work is also showing that stateside carriers are finding success with their iPhone promotions, leading him to conclude that initial replacement sales are coming in better than expected. Walkley is betting that future upgrade cycles will be even stronger. 

Cupertino's on a roll

One can argue that Long and Walkley didn't have much of a choice here. Apple's stock has been on a tear since bottoming out in May, soaring 28% to close at $114.92 on Friday. Long and Walkley parked with price targets of $116 and $120 didn't make sense on bullish ratings. 

The two analysts would have to either lower their ratings to more neutral settings or push up their stock price goals. They're doing the right thing. The market's hot for Apple again, and Wall Street pros don't want to be on the wrong side of that bullish momentum.