Small-cap stocks can be volatile, and they're usually not as closely followed as the megacap stocks that dominate investors' attention. But the best deals are often found where few people are looking.

We asked three of our Motley Fool contributors to each discuss a small-cap stock that investors should buy in June. Here's what you need to know about Noble Midstream Partners (NBLX), Tanger Factory Outlet Centers (SKT -0.14%), and Axsome Therapeutics (AXSM 1.36%).

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Big-time yield and growth

Matt DiLallo (Noble Midstream Partners): The main draw of small-cap companies is that they typically boast big-time growth potential. That's certainly the case with midstream specialist Noble Midstream Partners. The master limited partnership (MLP) is on track to grow its earnings 63% through the end of next year, fueled by the anticipated completion of several expansion projects, including its investment in two large-scale, long-haul pipelines. That high-octane earnings growth rate could quickly push the company's market value out of small-cap territory.

Meanwhile, Noble Midstream should be able to continue growing earnings at a healthy rate beyond next year. Driving that view is its strategic position in two of the country's fastest-growing shale plays: the DJ Basin and Delaware Basin. As production in those regions keeps expanding, it will drive the need for the MLP to continue building out additional midstream infrastructure.

Noble Midstream's fast-paced earnings growth will provide it with significant cash flow. While the company will use some of that money to continue building new infrastructure, it also expects to keep increasing its high-yield dividend at a rapid pace. The MLP already has an above-average yield of 8.1%. However, it currently intends on increasing that payout at a 20% annual pace through 2022.

That above-average income stream that the company expects to increase at a fast pace should enable Noble Midstream to produce market-beating total returns, making it an ideal small-cap stock to buy this June.

A retail bargain

Tim Green (Tanger Factory Outlet Centers): This one isn't for the faint of heart. Tanger is a real estate investment trust (REIT) that owns a few dozen outlet centers across the U.S. Store closings and retailer bankruptcies have been hurting the REIT's results, and the company expects those pressures to continue. Tanger sees its average occupancy for 2019 coming in between 94% and 94.5%. That metric hasn't fallen below 95% in more than 25 years.

While the upheaval in the retail industry is taking its toll on Tanger's performance, it would be a mistake to lump the company in with second-tier shopping mall operators that are struggling for survival. Tanger's outlet centers offer discounts on brand-name merchandise, and the desire for a bargain will never go out of style. "In good times, people love a bargain, and in tough times, people need a bargain," reads Tanger's latest earnings presentation.

Tanger not only survived the financial crisis last decade, but it managed to keep growing its dividend. The company has raised its dividend annually since its initial public offering in 1993, a sign that the business model is more resilient that the market assumes.

Shares of Tanger have taken a beating recently, down nearly 60% from their three-year high. And the stock could keep falling, pushed lower by fears about the retail industry or the next recession. But with shares trading for around 7.5 times the company's expected funds from operations this year, and with a dividend yield now topping 8%, investors able to stomach the volatility should jump on this small-cap bargain.

Three phase 3 trials wrapping up by year-end

Maxx Chatsko (Axsome Therapeutics): Shares have gained over 700% since the beginning of the year, but investors willing to tolerate volatility and a high degree of risk might be handsomely rewarded for taking a small position in Axsome Therapeutics.

The stock rocketed out of obscurity after promising data was reported from a phase 2 trial evaluating its lead drug candidate, AXS-05, in major depressive disorder (MDD) in January. The results drew comparisons to Sage Therapeutics, which has earned a market valuation of $8.7 billion for its own unique approach to treating depression disorders. Axsome Therapeutics is valued at about $800 million today.

What's intriguing about AXS-05 is the simplicity of the approach. The drug is a combination of a common cough suppressant called dextromethorphan and a common antidepressant called bupropion. Both interact with receptors in the central nervous system, while the latter increases the effectiveness of the former. Importantly, the combination allows for an easy-to-use oral formulation.

The drug's composition isn't the only thing that's simple. Axsome Therapeutics announced in May that the U.S. Food and Drug Administration granted AXS-05 the coveted Breakthrough Therapy Designation. That means the phase 2 data in MDD will be treated as if it were collected from a phase 3 trial when a new drug application is submitted, which means the company can now focus on running one pivotal study in MDD instead of two.

It's going to be an exciting seven months. Axsome Therapeutics expects to have data from three phase 3 studies -- AXS-05 in MDD, AXS-05 in treatment-resistant depression, and AXS-07 in migraine -- by the end of 2019. While it remains a risky and speculative bet, it could be fun to hold a small position in the company as clinical results are announced.