2019 was a great year for stock investors. The S&P 500, a good proxy for the U.S. stock market, delivered 31% in total returns. That was one of the best years in the past decade, and a strong bounce back after losing value in 2018.

Growth stocks did even better. The Vanguard Growth ETF, made up of 280 growth stocks, was up 37% in 2019, and I expect many growth stocks should continue delivering big gains for investors this year.

Three in particular that I like are Clean Energy Fuels (CLNE -1.31%), Tellurian (TELL -2.79%), and NV5 Global (NVEE -0.20%). Not only do I like their prospects for the coming year, but I expect they should reward investors for years to come. Keep reading to learn why you should consider them for your own portfolio.

Man holding model rocket as it starts to take off.

Image source: Getty Images.

A bounce-back year for Clean Energy Fuels

2019 was a solid year for Clean Energy Fuels. The company, which specializes in providing natural gas -- both the fossil fuel and renewable natural gas -- for transportation applications, grew fuel sales and moved even close to profitability. Even better, the company looks like a lock to report a full year of positive operating cash flows when it announces fourth-quarter earnings.

Just as impressive, this positive progress continues, even as battery-electric and hydrogen continue to get most of the headlines. Simply put, Clean Energy Fuels -- and natural gas, particularly renewable natural gas from farming waste and landfills it sells under the Redeem brand -- continues to grow, even as it remains below the radar for many investors as the most economically viable alternative to diesel.

Side of transit bus with Clean Energy Redeem logo.

Image source: Clean Energy Fuels.

So what makes now a good time to buy, and 2020 likely to be a good year for the company? In addition to fuel sales growth, improved operations, and what is anticipated to be another record year for Redeem, Clean Energy got some great news in December, when Congress reinstated an alternative fuels tax credit that had expired in 2017. It could be worth as much as $60 million to the company for 2018 and 2019 and another $25 million to $30 million in 2020.

This massive cash infusion will allow the company to fully pay down $55 million in debt coming due later this year without having to touch the $100 million already on the balance sheet.

Put it all together and Clean Energy is about to go from good shape to great shape. If management can put that extra cash to work expanding the market for natural gas vehicles, 2020 could be a banner year, kicking off a multiyear move from market building to big profits.

Four pipelines running through a dirt trench.

Image source: Getty Images.

Time for Tellurian to break ground

At this point in its existence, Tellurian remains little more than a great business plan. To date, the company, which aims to be one of the biggest liquefied natural gas (LNG) exporters in the world, has yet to turn a single cubic foot of natural gas into LNG, much less sell any. It still has to raise billions of dollars and then build its Driftwood LNG plant and pipeline before that happens.

But the company has reached some important milestones over the past year, including getting all necessary regulatory approvals and completing significant engineering work to prepare to move forward with construction of Driftwood. That makes 2020 a critical year for Tellurian's future, and moves it closer to reaching its potential as a cash-cow LNG export giant.

Don't get me wrong: Tellurian remains a high-risk, high-reward stock. Because it has essentially no existing operations, the risk of permanent losses is high. But it has a management team with a track record of building a successful LNG export business, and I think that helps offset much of the execution risk. And at recent prices, shares trade for a substantial discount to the company's future cash flow projections of $8 per share.

At a reasonable cash flow multiple of eight to 10 times, Tellurian shares could be worth $65 to $80 in five years. Trading for less than $7.50 today, that's a massive amount of upside -- if you can stomach the risk.

NV5 Global is putting it all together

Since going public, engineering and infrastructure consulting company NV5 Global has grown revenue. Revenue is up 664%, and investors have enjoyed almost 600% in gains.

However, the stock finished last year down 17% as the company's earnings growth slowed under the weight of integrating a number of acquisitions. NV5 acquired nine different companies in 2019, including the big $318 million purchase of geospatial data firm Quantum Spacial at the end of the year.

For context, NV5 has a market cap of less than $650 million as of this writing. Buying a $318 million business is no small potatoes, particularly with many investors concerned that the company is adding new companies faster than it can integrate them into NV5.

Aerial view of cloverleaf highway interchange.

Image source: Getty Images.

And while there's certainly risk when companies try to grow by acquisition, I think NV5 founder and CEO Dickerson Wright deserves the benefit of the doubt. His track record of picking the right companies to add to NV5 is excellent, and the company's past history of improving them is solid. NV5 shares are down 41% from the all-time high reached in mid-2019. I think the sell-off is overdone based on the company's history of execution and the expected growth in demand in coming years for infrastructure consulting, engineering, and surveying that make up the company's core business.

While the early part of 2020 could see a lot of focus on integration, I think we can expect to see double-digit growth as those investments deliver in the second half of the year and beyond. That's why I recently doubled my stake in the company, and think it should be on growth investors' short lists.

Big trends, great management, and huge opportunity

While these are three very different companies, they share some common traits. That includes talented management with skin in the game in the form of personal stakes in the companies they run and big trends that should lead to years of opportunity. None are risk-free, and they're all likely to prove volatile investments. But that's the price of admission if you want to capture market-beating returns.