If you entered 2020 not knowing whether you had the stomach to be an investor in the stock market, your question has almost certainly been answered. That's because we've witnessed record-breaking volatility in equities this year, including the fastest bear market decline in history, as well as the strongest quarterly rally in decades.

The thing about volatility is that it opens the door for long-term investors to buy into great companies on the cheap. While I'm not saying the road to riches won't be filled with speed bumps, investors who look beyond the near term are often handsomely rewarded for their patience.

Plus, what's remarkable about investing in the stock market is that you don't need to be rich to become rich. Starting out with even $500 can be more than enough to put you on the path toward financial freedom.

The question is, where to put your $500 to work? Although tech stocks with triple-digit share prices have proved unstoppable for months, perhaps the most intriguing bargains can be found in stocks with share prices under $10. Below are three great stocks you can buy right now that all sport a single-digit share price.

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Sirius XM

One of the smartest stocks investors can buy right now is satellite-radio operator Sirius XM (NASDAQ:SIRI), which can be had for just $6 a share.

As some of you may know, Sirius XM is the only satellite-radio company. This doesn't mean it's completely devoid of competition, as terrestrial and online radio operators are always fighting for listeners, just the same. But having a satellite system in space means that Sirius XM has relatively fixed transmission and operating expenses, no matter how many new net-paying subscribers the company enrolls. Over time, this is a formula for slow-but-steady margin expansion.

What's even more exciting for Sirius XM shareholders is how the company generates its revenue. Despite acquiring Pandora, an ad-based streaming content provider, in February 2019, the vast majority of Sirius XM's revenue is generated from subscriptions.

During the coronavirus disease 2019 (COVID-19)-impacted second-quarter, ad revenue slumped 31% from the prior-year period, but subscription sales actually rose 3%. Since subscribers are less likely to cancel their plans when economic hiccups arise, the fact that they've accounted for 83% of Sirius XM's sales in 2020 (year to date) suggests Sirius XM is uniquely positioned among radio operators to survive a recession and emerge stronger than before

Sirius XM has exceptional plan-pricing power, so its shareholders should expect consistent mid-single-digit growth.

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Annaly Capital Management

Though mortgage real estate investment trusts (REITs) haven't exactly been on anyone's shopping list in recent years, Annaly Capital Management (NYSE:NLY) should be.

Mortgage REITs like Annaly borrow at lower short-term interest rates, then acquire assets or lend at a higher long-term yield. The difference between this long-term yield and short-term borrowing rate is the net interest margin, and the wider the gap, the more profitable mortgage REITs typically are.

In Annaly's case, the yield-curve inversion from last August was the absolute worst thing that could have happened, as it meant short-term borrowing costs were eclipsing long-term yield opportunities, at least for a brief period of time. However, history has shown that as the U.S. economy rebounds from a recession, this gap between long-term and short-term yields tends to widen considerably over time. This means Annaly's net interest margin should broaden pretty significantly over the next couple of years.

Furthermore, mortgage REITs typically buy two types of assets: agency and non-agency. Agency assets are backed by a government agency in case of default but typically have lower yields, whereas non-agency assets have no federal backing but offer superior yields. Annaly almost exclusively invests in safer agency-only mortgage-backed securities. This means it's protected in the event of defaults, which has allowed the company to use leverage to its advantage. 

Having averaged close to a 10% dividend yield over the past two decades, Annaly is an income seeker's dream stock.

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CalAmp

Another great stock under $10 that investors can buy with confidence is mobile technology-solutions provider CalAmp (NASDAQ:CAMP).

As with most cyclical companies, CalAmp has faced some big challenges due to the coronavirus pandemic and the threat of ongoing trade-war instability between the U.S. and China. The good news is that many of these issues are in the process of resolving, which will clear a path to steady growth and profitability for Internet of Things up-and-comer CalAmp.

On the production side of the equation, CalAmp has been aggressively reducing its reliance on China for its telematics equipment. At one time, Chinese imports accounted for between 70% and 80% of the company's telematics solutions. This is now down to closer to 50%. With CalAmp able to outsource beyond China, the potential for geopolitical risk to disrupt its bottom line has been greatly reduced.

Additionally, we've (finally) witnessed CalAmp's management team transition out of automotive vehicle financing and into considerably higher-margin, consistent cash flow ventures. More specifically, the company's software-as-a-service (SaaS) subscriptions are helping businesses better manage and track their fleets, as well as improve supply-chain visibility.

Even with the company's sales down 10% to $80 million in the quarter ending in May, SaaS revenue was up 10% from the prior-year period to $28 million. As SaaS grows into a larger piece of the pie, CalAmp's margins are going to climb

In short, connected devices are a huge opportunity this decade, and CalAmp is right in the thick of it.