It's been a forgettable year for the wider market, with indexes appearing set to end 2018 roughly where they started. Many individual stocks have done far better than that, though, and a few of those standout investments appear set for further gains into 2019.

Let's take a look at the 2018 market-beaters that are brimming with potential heading into the new year.

Netflix is growing

As crazy as it might sound, many shareholders are likely disappointed with the over 40% increase that Netflix (NASDAQ:NFLX) shares saw in 2018. The stock had more than doubled at one point, after all, and was up 120% in early July.

A family watching TV on the couch

Image source: Getty Images.

The two earnings reports that followed were not well received by Wall Street, even though they did nothing to change the bright growth picture for the streaming video giant. Sure, subscriber gains fell well below expectations in the fiscal second quarter in a performance that CEO Reed Hastings and his team admitted was "not stellar."

However, the company followed that up by blowing past targets in the third quarter. Overall, Netflix has added 19.5 million new users through the first three quarters of the year, compared to 15.5 million in the same period last year. Combine that accelerating growth trend with rising profitability as customers happily pay higher subscription fees, and you have the potential for soaring earnings over the long term.

Lululemon has brand power

lululemon athletica (NASDAQ:LULU) has given investors plenty of good reasons to bid the stock higher this year. Sales growth has surpassed management's targets in each of the last three quarters, for one, capped by a 17% spike in the most recent quarter. The yoga-inspired apparel specialist is performing particularly well in the online sales channel, which jumped 44% last quarter and now accounts for over one quarter of the broader business.

Lululemon is turning more online browsers into apparel buyers these days, and that conversion boost should keep lifting sales results in the year to come. But the bigger growth driver will be how well its products can resonate with its customer base, especially over the holiday season. The good news is the retailer has positive momentum here, as most of its recent introductions are selling well, and at full price.

Executives are targeting another uptick in profitability for the holiday quarter, with further gross margin gains likely over the next few years. Looking further out, lululemon could have a much larger sales base in a decade after it expands into international markets and beyond its core female demographic.

Wayfair is winning market share

High-growth stocks are a volatile group, but that risk profile is even higher for Wayfair (NYSE:W). Yes, the online home furnishings retailer is on a roll when it comes to market-share gains, with sales rising by over 40% in each of the last three quarters. And that growth has come despite intense price-based competition from rivals like Overstock.

A modern living room.

Image source: Getty Images.

Yet Wayfair has posted a net loss in each of the last four fiscal years, and soaring spending in 2018 all but ensures a similar result in that outing.  

Still, investors who can accept that cloudy earnings picture could enjoy strong returns as the e-tailer reaches global scale in the coming years while solidifying its early lead in the core U.S. market. The spending boost makes perfect sense, after all, since it is helping Wayfair soak up market share in a fragmented industry. Several potential challenges could derail the stock's rally, including if the company resorts to deep discounting during the holiday shopping season. Over the long term, though, Wayfair has valuable assets, including a large customer base, a strong delivery infrastructure, and a flexible selling platform, that should serve it well as it widens its addressable market by entering new geographies and new product niches in 2019.

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.