Theoretically, a stock's absolute price shouldn't matter. In the same sense that two $10 bills are equivalent to one $20 bill, two shares of a $10 stock is the same as one share of a $20 stock. A stock's price can be manipulated by stock splits and reverse splits anyway, and no matter what, a stock's price is ultimately a reflection of what the market thinks of that company's foreseeable future.

In reality, though, there's a modest amount of evidence that lower-priced stocks do outperform their higher-priced counterparts on average. It's also fun to be able to tell others at cocktail parties that you stepped into the right name for less than a tenner.

To that end, here's a look at three great stocks priced at less than $10 per share that investors may want to consider as high-octane additions to their portfolios.

Man handing over a ten dollar bill

Image source: Getty Images.

1. Zynga is more relevant now than it's ever been

Mobile (and desktop) casual game company Zynga (ZNGA) was all the rage in 2009, not only when it was new, but when it took the gaming arena by storm -- and by surprise -- with hit titles like Farmville and Cityville. Since then, the game publisher's faded from its former glory, but don't mistake fewer and less scintillating headlines for failure. Last year's revenue was another record-breaker, driven by new games like Merge Magic! in addition to still-relevant titles such as Words With Friends and Zynga Poker. The arena may be more crowded and a lot noisier now, but Zynga remains a stalwart.

That said, as strange as it may seem to hear it, the coronavirus pandemic may prove to be an incredibly powerful growth driver for this already-potent company.

While lockdowns have been largely lifted, millions of people all over the world are still choosing to huddle at home rather than get out. A recent survey conducted by consulting firm EY, for instance, suggests that about half of consumers expect significant and lasting change to their lives even once the COVID-19 contagion is in the rearview mirror. In the meantime, a huge segment of consumers has already made it clear that video gaming is a go-to option for at-home entertainment. Wireless name Verizon has reported several times since the pandemic started that gaming-related traffic on its networks was up double digits, if not by triple digits, year over year, and mobile consumer measurement firm Adjust says mobile game downloads were up 75% year over year during the first quarter.

It's not tough to connect the dots. While the pace of growth won't hold forever, that surge in the sort of entertainment Zynga offers appears built to last -- particularly thanks to some key acquisitions.

2. OPKO Health finds a bridge to Somatrogon

It wouldn't be accurate to say that OPKO Health (OPK) is a highly diversified healthcare company. It's only got two major revenue-bearing products to speak of. One is Rayaldee (or calcifediol), sold in a controlled release capsule as a treatment for certain types of kidney disease. The other is its 4KScore test, used to identify prostate cancer. Both are fine products but weren't enough to translate into revenue growth for OPKO Health last year.

COVID-19 has breathed new life into OPKO, though. While most of the rhetoric to date has been about finding a vaccine, OPKO has snuck in as a preferred provider of coronavirus testing solutions. Earlier this month, it was awarded a contract from the Centers for Disease Control and Prevention to provide COVID-19 tests. It's also been selected by Major League Soccer, the NBA, and the NFL to provide coronavirus tests, and by a bunch of other organizations before that.

Those are temporary deals, and the sports-related contracts aren't particularly big ones. But it's the sort of high-profile victory that can put a company back on the radar, which in turn opens doors to future opportunities. Between now and then, double-digit revenue growth expected for this year and next is also expected to push OPKO Health out of the red and into the black next year. That progress will not only provide the liquidity needed to continue its trials of growth hormone deficiency treatment Somatrogon (expected to be submitted to the FDA later this year), but could make it easier for OPKO to raise any necessary funds through a secondary offering.

The human growth hormone therapy market, by the way, is expected to be worth something on the order of $7 billion to $8 billion within a few years.

3. After underestimating looming changes, ADT has evolved

Finally, add alarm company ADT (ADT 0.16%) to your list of great stocks priced below $10 per share to consider.

Credit has to be given where it's due. Self-service alternatives like SimpliSafe and Ring rattled the more conventional names like ADT or Vivint. The advent of mobile phones, wireless connectivity, and dirt-cheap circuit boards was just something the previous powerhouses in the business didn't plan on. ADT managed to grow its top line last year, to the tune of 12%. Operating income slipped, though, and generally accepted accounting principles (GAAP) losses remain the norm.

The company, however, has really turned up the heat lately in areas where DIY doesn't quite work. That's institutional-level solutions, and even in the digital realm. Discount retailer Dollar Tree was named a commercial customer last month, and early this year the company fully figured out that most consumers are now worried that so-called smart home technology may not be nearly as secure as they'd like. ADT has been working hard (or acquiring) on that front too.

Perhaps most noteworthy of all, in May the company made a deal with online shopping name Instacart to provide mobile safety solutions for its employees who work remotely, shopping and making deliveries for the company's customers. In simplest terms, these shoppers will have an alarm system built into their smartphones.

Given how outsourced shopping and delivery is becoming a mainstream service that requires an army of autonomous workers, ADT is helping shape an important new aspect of personal security.