Predator Drone. Source: U.S. Air Force.

This article was originally published June 18, 2015. It was updated on Dec. 21, 2015, to account for ongoing shifts in the drone industry.

Unmanned aerial vehicles -- or drones, as they're commonly known -- remain in their infancy. Although the U.S. military has used them in various capacities for several decades, their civilian and commercial use remains limited. That should change soon. Research company The Teal Group believes spending on drones will double over the next 10 years, totaling more than $93 billion in the process. 

For investors, the coming drone revolution represents an opportunity. Although it's impossible to pick the winners and losers at such an early juncture, the following four stocks could benefit as drones become more widely used.

A drone manufacturer
AeroVironment (AVAV -0.66%) is the closest thing investors will get to a true, "pure-play" drone company. AeroVironment designs and manufactures drones, and a significant percentage of its revenue comes from the sale of these drones, primarily to the U.S. Department of Defense. That said, not all of its revenue comes from drones. AeroVironment also has an energy business -- it supplies charging systems for electric vehicles. Last quarter, roughly 12% of AeroVironment's revenue came from the sale of these systems.

Still, that means nearly 90% of AeroVironment's revenue is coming from its drone business, which should allow it to benefit as the demand for drones surges in the years ahead. Currently, AeroVironment is largely a government contractor, with little exposure to the commercial drone market, but management sees the commercial side to be an area of great potential growth.

AeroVironment has been working with some companies -- including oil giant BP in a limited capacity (using drones to inspect pipelines in Alaska) -- but intends to expand to other companies and other regions in the near future. Unfortunately, AeroVironment's management has declined to offer hard figures on this side of its business. On the company's last earnings call, CEO Tim Conver admitted that it wouldn't add meaningful revenue this fiscal year, as its commercial drones remain in development.  

GoPro plans to break into the drone market
0% of GoPro's (GPRO -4.42%) 2015 revenue will come from the sale of drones. Its 2016 revenue mix, however, could be quite different, as GoPro intends to release its first drone next year. Unlike AeroVironment's products, it will be aimed explicitly at the consumer drone market. If nothing else, GoPro has a strong brand, and its core market (tech-minded, outdoorsy consumers) could have significant overlap with the consumer market for drones 

GoPro's quadcopter, the Karma, is slated to make its debut in the first half of 2016. Important details (like retail price and specs) remain unknown, but GoPro has released footage of its drone in action. On the company's most recent earnings call, CEO Nick Woodman said it would appeal to a subset of GoPro's existing customer base, and that its relationship with distributors and retailers would give it an advantage.

There's clearly a market for consumer drones: In May, Chinese company DJI raised $75 million at an $8 billion valuation. DJI is the current market leader for consumer drones -- it makes most of the models you'll find for sale on Amazon (AMZN -0.27%). DJI's revenue has been growing rapidly in recent years: The company expects to generate more than $1 billion in sales this year, up from just $130 million in 2013, according to The Wall Street Journal [subscription required].

Last year, GoPro's revenue totaled roughly $1.4 billion, and analysts expect GoPro to generate about $1.7 billion in sales this year. Both GoPro's core action camera business and the consumer drone market are growing rapidly, but if GoPro could become a meaningful participant, its annual revenue could rise 50%-100%. 

Tegra could power the drones of the future
NVIDIA (NVDA -0.47%) doesn't make drones, and it hasn't announced any plans to make one. But in the years ahead, NVIDIA could become a major supplier to the drone industry.

NVIDIA's mobile chip platform, Tegra, has been a relative failure when it comes to smartphones and tablets: Tegra-powered mobile devices are few and far between. Still, NVIDIA hasn't given up on Tegra; in fact, it's doubled down, rolling out a continuous slew of new Tegra models with ever-increasing power. The latest version of the Tegra, the Tegra X1, is among the most powerful mobile chips available. When NVIDIA announced it back in January, NVIDIA partnered with German automaker Audi to show how it could become the brains of tomorrow's self-driving cars.

Could it also become the brains of tomorrow's unmanned aerial vehicles? At the Consumer Electronics Show earlier this year, drone-maker Parrot showcased a demo of a new consumer drone concept that relied on the Tegra X1's predecessor, the Tegra K1. And last month, DJI announced Manifold, an embedded drone computer powered by the same chip. As the market for drones matures and their capabilities increase, drone makers may need increasingly powerful chips for their products. NVIDIA appears to be one chip maker actively courting the industry.

A new way to ship
But of all the companies that could benefit from drones, Amazon may have the most to gain. In November 2013, Amazon unveiled "PrimeAir" -- a concept in testing that would allow it to deliver its customers' packages with drones. Decried by some as a PR stunt -- the announcement came just days before the Black Friday shopping bonanza -- it nevertheless made it clear that Amazon has an avid interest in taking advantage of drone technology.

Last month, it reiterated its commitment. In an ad narrated by former Top Gear host Jeremy Clarkson, Amazon detailed how its drones would work, and promised a "whole family" of different models.

Many industries are likely to adopt drones, but online retail could be completely revolutionized by it. Amazon is a monstrous company, but it still lags far behind the likes of Wal-Mart, Kroger, and Costco in terms of total sales. Last year, Amazon's revenue totaled roughly $89 billion, including the sale of non-physical goods (digital books and movies) and cloud services. Costco's net sales, meanwhile, exceeded $110 billion. Online shopping has its perks, but having to wait even two days is still two days too many for plenty of shoppers. Near instantaneous drone delivery could be the final push Amazon needs to become America's largest retailer.

If you think drones have a bright future, Amazon may be among the best -- albeit indirect -- ways to invest.