We are less than two weeks away from the end of 2019, and many investors are already celebrating a great year. As of this writing (Dec. 18), the S&P 500 has delivered almost 30% in total returns. That's not only a strong bounce back from a 2018 that saw stocks fall more than 4%, but it's also one of the best years we've seen in the past decade. 

But I think savvy investors willing to take on some risk can still find incredible growth stocks. There are plenty of industries going through significant change, and most companies need help managing the technologies of the 21st century to remain competitive. 

Before the calendar switches to 2020, I plan to buy Datadog (NASDAQ:DDOG) and Telaria (NYSE:TLRA). I'll be buying the former for the first time, and adding shares to my existing -- albeit small -- position in Telaria. Both of these companies are positioned for big profits in the years to come as demand for their services skyrockets.  

Man holding toy rocket that starts to launch.

These two stocks could rocket much higher. Image source: Getty Images.

Making sense (and eventually money) of mountains of data

Companies now generate and have access to massive amounts of data. The problem for many businesses is that very often, managing and utilizing all that data is outside their core skills, and that can create all kinds of additional problems that limit a company's success.

This is where Datadog comes in. In short, the company provides a range of services to help companies better utilize and manage data, as well as find the valuable information from that data that can be used to improve the business. And so far, Datadog has proven very appealing to a growing base of customers. As my Fool.com colleague Brian Stoffel recently noted, Datadog's customer base is growing at an enormous rate, particularly among clients who spend more than $100,000 per year with the company. 

Taken another step further, Datadog is appealing because of its leadership. The two co-founders -- they founded Datadog based on real-world problems they experienced at other companies -- are its CEO and CTO (chief technology officer), and they own almost one-fourth of the company between them. 

Datadog made its debut on the public markets in September. It's still consuming cash and reporting losses, making it harder to value, and my expectation is that management will continue pouring cash into the business to support its incredible rate of growth. And that's almost certain to result in big volatility for the stock price as investors try to project its performance -- and its path to profitability. 

So this isn't a business for the faint of heart. But if you're looking for a great growth stock that could double or even triple in value over the next five years, Datadog looks like a solid candidate. That's why I intend to buy shares before the end of December. 

An important player in the future of TV advertising

The way people use their televisions is changing. The days of flipping channels on the remote aren't gone, but they're steadily making up less and less of how people watch TV as more viewers use streaming apps to consume what they want, when they want. 

Advertisers are taking notice, and starting to shift their spending to where the eyeballs are. Telaria is a key player in helping publishers make the most of their digital advertising inventory in what remains a very fragmented space -- and a high-growth one at that. Being a big player in a high-growth, fragmented industry gives Telaria an enviable position. 

Potentially the biggest opportunity for the company is in connected TVs, which represent less than 10% of TV advertising dollars. That number is expected to rise at double-digit rates for years to come as more viewers shift away from traditional TV or cable and the need for marketers to advertise on connected TVs grows. Connected TV revenue increased 44% in Telaria's third quarter alone. 

Moreover, Telaria's value proposition looks set to get a lot stronger, thanks to its agreement to merge with Rubicon Project (NYSE:RUBI) in early 2020. Rubicon Project is a major player in programmatic advertising, and combining that strength with Telaria's connected TV ad platform will make it the biggest company on the sell-side of programmatic advertising. 

This combined scale should prove an enormous advantage for the company as digital content producers look to maximize their ad inventory. 

The risk? Mergers don't always go well, and rarely exactly as planned. But my expectation is that this is a case of two good companies combining into what could be a truly great one. Their strengths complement one another, and should lead to significant competitive advantages that help content producers selling ad space, as well as marketers looking to get the most out of their spend. 

But even with that risk, the market-beating prospects look too good to ignore. The trend is decidedly in favor of rapid growth in programmatic ad spending, particularly on connected TVs, and Telaria is set to be a leader in this high-growth segment for years to come.