It may seem as if Netflix (NFLX 0.87%) has had a rough year. Between the onslaught of new services and falling short of its subscriber guidance (twice), 2019 might look like one to forget for the streaming service's investors. Reality has been far kinder than the headlines, however. Netflix stock has soared 23% this year with a pair of trading days left to go.

Netflix has historically been volatile, so there will always be ups and downs. Let's go over some of the things that can trip up the longtime market darling in the year ahead if they should rear their ugly heads into the frame.

Sandra Bullock donning a blindfold with a child actress in Netflix's Bird Box movie.

Sandra Bullock in the Netflix movie Bird Box. Image source: Netflix.

1. Missing guidance three quarters in a row 

Netflix stunned the market when it tacked on just 2.7 million subscribers in the second quarter, a little more than half the 5 million net additions that it was targeting. It justified the miss by pointing to a springtime price hike that helped boost average revenue per member, but it wasn't the end of the misses. The nearly 6.8 million global net additions that it served up in the third quarter were 3% shy of its earlier outlook. 

It would naturally be brutal if it fell short for the third time in a row when it posts its fourth-quarter results in a few weeks. The price-hike scapegoat has left the stable. It was shocking to see a company that has never missed more than one quarterly forecast in any given year prove mortal twice. But thrice, and it's time to reconsider CEO Reed Hastings' optimism. If Netflix can't read its own near-term churning trends more efficiently, it will be hard to trust what used to be lowball forecasts. 

2. Rivals can leave a mark

There has always been a lot of great content to stream online, but the marketplace is getting pretty crowded. Netflix is used to losing Emmy nods to original programming on Hulu and Prime, but Disney's (DIS 0.17%) bold foray into this niche last month has made it a force to watch. 

Disney+ topped 10 million subscribers by the end of its launch day, and that was before The Mandalorian became the service's first exclusive-content blockbuster. If Netflix was falling short of its subscriber guidance before Disney+, how will it hold up with Disney's massive content vault now available for roughly half of Netflix's cover charge?

The pipeline is also loaded with potential disruptors. HBO Max and NBC's Peacock have springtime rollouts planned, and the latter may disrupt the value proposition of streaming platforms by offering a free ad-saddled version. Netflix has more than a dozen years of streaming data in its arsenal, but there are a lot of hungry rookies out there vying for your limited viewing time. 

3. A price cut can dent valuations 

A big key to Netflix's monster stock gains in recent years is its surprising pricing elasticity. It has been able to push through four price hikes since early 2014, bumping up the cost of its most popular streaming plan by 63% along the way. There aren't too many entertainment platforms with that kind of pricing power, and people generally aren't mad about it the way that they typically are with much smaller hikes by cable and satellite TV providers. 

Things may be different now for Netflix. A price of $12.99 a month for its common streaming offering may not seem like much, but Disney+ at $6.99 is tugging the value proposition of a premium platform lower. Disney's own bundle that matches Netflix's price point by offering Disney+, ESPN+, and its ad-supported Hulu is another product that will keep Netflix in check. Pricing pressures will only get worse, naturally, if the economy takes a recessionary turn

Netflix was already stretching the limits of its pricing elasticity before the mid-November launch of Disney+. We know this is a problem because of how badly Netflix misjudged churning activity following its last increase.

However, Disney offering discounted annual plans has to leave Netflix at least thinking about either following suit or finding ways to bang out a more competitive plan. Wall Street loved the price hikes, and it's fair to say that the Street will not like it if and when things go the other way.