The S&P 500's hottest stock of 2015 -- and 2013, for that matter -- has cooled off this year. That hasn't stopped one Wall Street pro from warming up to the opportunity.

Piper Jaffray analyst Michael Olson upgraded shares of Netflix (NFLX -1.74%) on Tuesday, going from neutral to overweight on the leading premium video-streaming platform. Piper Jaffray's price target of $122 implies 33% in upside based on Tuesday's close.

Last year's market darling has been mortal in early 2016. It's trading 20% lower year to date, off by 31% since peaking two months ago. Olson accepts the volatility, suggesting that these "periodic pullbacks" will be "attractive entry points" for opportunistic investors. 

Yes, stateside expansion has slowed. More than 4 million of the 5.59 million net additions that Netflix scored during the final three months of 2015 came from outside of the U.S. market. That's fine. Netflix is now available in 190 countries, and that's where the lion's share of its growth will come in terms of sheer subscriber numbers. 

Olson's model forecasts 142 million subscribers by 2020. Less than half of those -- 63 million -- will be U.S. accounts. Put another way, the number of domestic users could go from 60% of Netflix's total base today to less than 45% in five years.

This doesn't mean that the gravy days are over, even domestically. We'll probably be paying more for Netflix in five years. In fact, in a few months, the folks who were grandfathered in at $7.99 a month for two years back in the springtime of 2014 -- when Netflix initially bumped its monthly rate to $8.99, and then $9.99 -- will have to begin paying $9.99 a month if they want to continue to enjoy their streams in HD. A standard definition option at $7.99 a month will still be available.

No service is elastic, but if any subscription offering has improved its value during the past two years to merit an increase, it's Netflix. The sheer volume of original programming and widening catalog make it a no-brainer entertainment value. 

Let's also not assume that Netflix will be merely collecting monthly digital buffet fees in a few years. There are many new revenue streams that will be available to Netflix as it scales globally, if it should decide to whip out its oars and start paddling through them. 

This is the kind of rosy scenario that may seem hard to swallow at a time when the stock price is falling. Being bullish on Netflix now seems as unfashionable as being bearish on Netflix last year. Then again, aren't many of the bears on Netflix now the same ones who were wrong in 2013 and 2015?

Netflix's fundamentals are crumbling just because the cost of ownership is getting cheaper. The model still works, and that justifies Olson stepping up with an advantageous upgrade at a time when the market is going the other way.