Every investing style poses unique challenges. When it comes to growth investing, they have to do with identifying companies that have "fertile fields of growth," as famed investor Thomas Rowe Price once put it. Envisioning a world in the future, and trying to predict whether a particular company fits into this vision, is, no doubt, a tall order.

So we asked three of our investors to each highlight a stock they see as one with incredible growth potential in the future. Here's why they selected Zillow Group (Z 0.73%) (ZG 0.74%)Cara Therapeutics, Inc. (CARA -5.87%), and First Solar (FSLR 2.94%).

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This stock will make you feel at home

Dan Caplinger (Zillow Group): The real estate market has rebounded sharply since the housing bust a decade ago. One of the things that has changed about the market: There is more information available to buyers and sellers. Zillow Group was a pioneer in providing home pricing estimates and now comprises a large group of online websites that include Trulia, StreetEasy, Realestate.com, and its namesake Zillow site.

Zillow does a lot more than just offer its Zestimates. Agent services are a key source of revenue, and Zillow also brings in money from mortgage relationships and rental properties, as well as display advertising. The company has done an especially good job of wooing high-value Premier Agents to its fold, almost doubling the amount of sales it makes to agents spending $5,000 or more per month on its services. With monthly average unique visitors climbing above the 175-million mark in the third quarter of 2017, Zillow already has a strong user base, and new features, like 3D home tours available on mobile devices and an instant-offering service that could connect sellers to investors, could spur even further growth. With housing still going strong, Zillow is leaving no stone unturned in its search for the best opportunities.

Some catalysts to look forward to

Cory Renauer (Cara Therapeutics, Inc.): This clinical-stage biotech doesn't have any approved drugs to sell yet, but it does have a candidate in late-stage clinical trials that could help stem America's opioid epidemic. During an early head-to-head study, patients were significantly less likely to report "liking" Cara's pain- and itch-relief candidate, intravenous CR845, than they were the highly addictive opioid drug Talwin.

Cara Therapeutics stock rose sharply when IV CR845 became the first drug to significantly reduce chronic itching symptoms common among dialysis patients. Investors can look forward to several big catalysts that could send the stock soaring again in 2018. A late-stage study for the chronic itching indication should begin any day now, and another study with the same candidate as a reliever of acute postoperative abdominal pain should have data next year as well.

Cara's stock price slipped earlier this year when a study of patients with chronic knee and hip pain treated with CR845 reported mixed results. While I think the oral version still has legs, success in either late-stage trial with the IV version could eventually lead to more than $300 million in annual sales. Biotechs tend to trade around mid-single-digit multiples of annual sales, which suggests this stock could soar several times higher over the next few years.

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Data by YCharts.

Up more than 100% in 2017, this solar stock is still a standout value

Tyler Crowe (First Solar): When a company's stock climbs as much as First Solar's has in a single year, it might hint at the possibility that the stock is due to slow down. That may not be the case for the United States' largest manufacturer of solar panels. Not only is there a lot of growth opportunity in the solar industry ripe for the taking, but First Solar shares still look relatively cheap.

Much to the surprise of industry experts and others who were predicting a bad year for the solar industry, 2017 has proven to be another good year of growth. A continued decline in the cost per watt for solar has made it a less expensive power source than all fossil fuels and has led to global installations hitting close to 100 gigawatts for the year. While panels manufacturing -- First Solar's domain -- will likely continue to go through periods of over- and undersupply, as it has over the past few years, the industry is growing so fast that the opportunity to expand is there in spades.

Investors have been bidding up shares in large part because First Solar's sales have been much more robust than originally anticipated, but the company could still have a lot of room to run. One thing to consider with this $6 billion company is that it currently has just over $2 billion in cash on hand and barely any debt outstanding. That suggests the company has an immense amount of capital to deploy over the next few years to either upgrade its existing manufacturing facilities for newer panel models or to expand production capacity. What's more, it won't have to use debt, as many of its peers have (a move that has led several of them to bankruptcy).

Between now and 2040, about $10.2 trillion will be spent on new energy sources, and about three-quarters of that will go to renewable sources, according to estimates from Bloomberg New Energy Finance. This is an immense pie from which First Solar can carve off a slice for itself, and suggests there are much-better days ahead for this stock.