The end of 2018 has been a difficult time for investors. After spending much of the year hitting all-time highs, each of the major indexes has spent the past three months in retreat. In addition to the long-awaited correction, the NASDAQ slipped briefly into bear market territory, fanning fears that stocks might have further to fall.

All is not lost, however. The vast amount of investor wealth is made by buying quality companies when they are on sale. "Being greedy when others are fearful," one of Warren Buffett's oft-quoted axioms, is easier said than done. Let's look at three stocks with massive opportunities that investors should consider before the market comes to its senses: Amazon.com (NASDAQ:AMZN), Netflix (NASDAQ:NFLX), and NVIDIA (NASDAQ:NVDA).

Downward trend arrow over stock symbols.

Image source: Getty Images.

E-commerce and so much more

While digital sales produce the majority of Amazon's revenue, the company offers something that many investments can't: optionality. In simplest terms, optionality is when a company has multiple paths to success, and Amazon offers a compelling example.

The most obvious instance is that of Amazon Web Services (AWS), its cloud computing segment. For the first three quarters of this year, AWS generated more than 11% of Amazon's revenue and 59% of its operating income, with operating margins of more than 28%. 

Amazon recently became the third-largest digital advertiser in the U.S. and is expected to generate more than $10 billion in ad sales in 2018. With just 4% of the digital ad market, Amazon has plenty of room to grow. 

There are other opportunities as well, including a growing list of physical stores, such as Whole Foods, Amazon Go cashierless convenience stores, bookstores, and 4-Star, which features the most popular items from its e-commerce store. The company's foray into business-to-business commerce (B2B) is also thriving, expected to top $10 billion in sales annually

Amazon has lost nearly a third of its value in the recent market turmoil. Considering the company's multiple paths to success, investors should get it now -- while it's on sale.

Streaming profits

Disrupting an existing industry has always been one path to success. After first sending the video rental store into irreparable decline, Netflix has set its sights on linear television. When the company introduced streaming video just over a decade ago, it would have been difficult to predict just now successful Netflix would become. The company now counts nearly half of all U.S. households as customers and has its sights set on the world.

A look at some of the company's earliest international markets suggests Netflix will ultimately be successful. Surveys in the U.K., Brazil, Germany, and France show impressive adoption rates: 56%, 77%, 37%, and 35%, respectively, of respondents reported watching Netflix.

A couple cuddling on the couch, eating popcorn, and looking at a laptop.

Image source: Getty Images.

The company isn't taking its foot off the gas, either. Netflix recently launched a number of highly successful movies and television shows in India and dropped its first-ever original series in Turkey. The company is expanding its content production in Europe and plans to add programs from Africa in the coming year. 

Netflix's global content bets are paying off, with subscribers growing 25% year over year in the most recent quarter, while revenue increased by 34%. Worldwide, paid subscribers topped 137 million, with more joining every month.

In spite of that impressive growth, Netflix has lost about 40% of its value since achieving all-time highs earlier this year, but its worldwide opportunity remains. Talk about throwing out the baby with the bathwater!

Powering the AI revolution

One of the biggest trends over the past couple of years has been the evolution of artificial intelligence (AI). A number of factors have played into its exponential growth, including better algorithms, larger data sets, and faster processors -- and the increase in processor speeds comes courtesy of NVIDIA. The company cornered the industry with the massive parallel processing capabilities of its graphics processing unit (GPU). The ability of the GPU to process significant amounts of data at lightning speeds was the answer AI researchers were looking for.

NVIDIA saw the writing on the wall and turned its attention toward AI -- without ever losing sight of its bread-and-butter gaming market. The company developed new products that answered the unique data-intensive needs of AI but also created companion software so that those building AI algorithms didn't have to reinvent the wheel.

These cutting-edge GPUs are also the processors of choice for the digital transformation occurring in business. More and more businesses are making the move to cloud computing, and NVIDIA GPUs can be found in every major public cloud. 

Growth recently decelerated due to declining demand in the cryptocurrency market and was compounded by recent market uncertainty. These have taken a toll on NVIDIA stock, which has lost more than 50% of its value over the past 90 days. The company still sits at the intersection of several significant trends, so I think it represents a big opportunity at these levels.

Final thoughts

Each of these companies is a leader in its respective field and has significant opportunities ahead. With the market in correction and some indexes flirting with bear market territory, there's no way to know for sure that we've reached a bottom. That said, investors should consider initiating positions or adding to these three companies -- before the market comes to its senses.