For the past 17 months, it's not been easy to be a marijuana stock investor. While there's little question that cannabis can be one of the fastest growing industries this decade, every industry needs time to mature. Right now, pot stocks are navigating their way through that maturation phase -- and let's just say it hasn't always been pretty. To our north, Canada has blown its chance to be the adult-use legalization blueprint for the rest of the world. Meanwhile, in the U.S., high tax rates have made it difficult for licensed producers to compete against low black-market prices. And I'd be remiss if I didn't mention the lack of traditional financing options available to marijuana stocks throughout North America. Image source: Getty Images. These cannabis stocks were blazing hot in August Yet, in spite of these adversities, certain cannabis stocks are thriving, at least based on a screen of pot stock returns in August. More specifically, the investment community witnessed 10 marijuana stocks blaze higher by at least 13% in what's historically been a ho-hum month for Wall Street. In descending order, and rounded to the nearest whole number, these top-performers are: GrowGeneration (NASDAQ: GRWG): Up 89% Trulieve Cannabis: 41% Planet 13 Holdings (OTC: PLNH.F): 25% Jushi Holdings (OTC: JUSHF): 20% Cresco Labs (OTC: CRLBF): 20% Columbia Care: 18% Innovative Industrial Properties (NYSE: IIPR): 18% Harvest Health & Recreation: 17% Green Thumb Industries: 14% Valens Company: 13% Why these 10 cannabis stocks and not the dozens of other pot stocks to choose from in August? Let's take a closer look. Image source: Getty Images. It's really all about the U.S.A. The first thing you may have noticed about the top-performing pot stocks in August is that investors are really optimistic about the U.S. weed industry and not so much about Canada's. With the exception of hemp and cannabis processing company Valens, there isn't a single company on this list that's focused on Canada. Honestly, this shouldn't be that much of a shock considering the U.S. population is nearly 10 times the size of Canada. A considerably larger adult population should allow peak sales for the U.S. cannabis industry to run circles around Canada's pot industry. The U.S. is also home to the largest marijuana market in the world (by sales), California. Although California will play a role in the growth potential of many of the above names, it's an especially important state for multistate operator (MSO) Cresco Labs. Though Cresco opened eight dispensaries in Illinois, its growth strategy hinges on getting its proprietary pot products into more than 575 dispensaries in the Golden State. Cresco's purchase of Origin House earlier this year is the key to success, since Origin House held one of only a few marijuana distribution licenses in California. Image source: Getty Images. Operating results matter Another important point that can't be overlooked is that operating results actually matter now. For years, promises of increased capacity, brand-name partnerships, and international exports proved more than enough to send valuations higher. But with Canada legalizing recreational weed and two-thirds of U.S. states giving the green light to cannabis in some capacity, tangible results are now mandatory. The big winner this past month, GrowGeneration, soared because it delivered jaw-dropping second-quarter operating results. GrowGeneration, which operates more than two dozen stores that provide hydroponic equipment, as well as lighting, soil, and nutrient solutions to growers, reported a 123% surge in Q2 sales to $43.5 million. Perhaps more important, GrowGen delivered a 166% increase in year-over-year earnings before interest, taxes, depreciation, and amortization (EBITDA), and produced generally accepted accounting principles (GAAP) net income of $2.6 million, which also more than doubled the year-ago quarter ($1.1 million). Marijuana-focused real estate investment trust Innovative Industrial Properties was also virtually unstoppable after announcing its second-quarter results. The company, which owns 61 properties (cannabis cultivation farms and processing facilities), generated revenue growth of 183% from the prior-year period, with adjusted funds from operations rising by 263%. Without question, Innovative Industrial Properties' aggressive acquisition strategy has played a key role in its rapid growth. Image source: Planet 13. Investors are fascinated with under-the-radar cannabis stocks But what I find most interesting about August's top-performing marijuana stocks is that investors are becoming increasingly interested in under-the-radar or unique pot stocks. For example, note the continued melt-up of under-the-radar MSO Jushi Holdings, which gained 20% last month. Jushi has licenses to open more than two dozen retail locations, with an emphasis on the Pennsylvania, Illinois, and Virginia markets. It has a vested management team that's put up its own money during previous rounds of financing, and reported 73% sequential quarterly sales growth in the June-ended quarter. With the company expected to turn the corner to positive adjusted EBITDA in the fourth quarter, investors appear more than willing to hop onboard. The same can be said for Planet 13, which offers cannabis enthusiasts a truly unique experience. The company's 112,000-square-foot SuperStore just west of the Las Vegas Strip in Nevada offers a consumer-facing processing center, a restaurant, an events stage, and plenty of floor space for consumers to pick out their favorite dried flower, derivatives, and paraphernalia. As a one-of-a-kind operating model, Planet 13 is seeing its average ticket increase in value over time. With the company recently announcing its intent to acquire a 45,000-square-foot cultivation facility in Nevada to go along with its existing cultivation assets, Planet 13 has the opportunity to become wildly successful in the Silver State's burgeoning marijuana market. Here's The Marijuana Stock You've Been Waiting ForA little-known Canadian company just unlocked what some experts think could be the key to profiting off the coming marijuana boom. And make no mistake – it is coming. Cannabis legalization is sweeping over North America – 11 states plus Washington, D.C., have all legalized recreational marijuana over the last few years, and full legalization came to Canada in October 2018. And one under-the-radar Canadian company is poised to explode from this coming marijuana revolution. Because a game-changing deal just went down between the Ontario government and this powerhouse company...and you need to hear this story today if you have even considered investing in pot stocks. Simply click here to get the full story now. Learn moreSean Williams has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Cresco Labs Inc., Green Thumb Industries, GrowGeneration, Innovative Industrial Properties, and Planet 13 Holdings Inc. The Motley Fool owns shares of Jushi Holdings. The Motley Fool recommends Valens GroWorks. The Motley Fool has a disclosure policy.Source