It's not difficult to find shares under $20 per share today. There are lots of cheap stocks on the market, even after the strong market recovery in the summer and fall of 2020.

With high risk comes big potential returns, but some low-priced stocks trade at a discount for a good reason. You must avoid those value traps in your search for strong companies that will survive the health crisis to thrive in 2021 and beyond.

Here are three high-quality tech stocks trading below $20 per share right now. Let me explain why they look like strong buys at these low prices.

A person views a pink piggy bank through a magnifying glass.

Image source: Getty Images.

LG Display: $9.23 per share

LCD and OLED screen manufacturer LG Display (NYSE:LPL) is the screen-building arm of Korean tech giant LG Electronics. The company makes high-quality screens in many markets, ranging from tablets and smartphones to big-screen television sets and in-car infotainment systems. Growth in any of these markets translates into good news for LG Display as well.

The stock rose 35% over the last 52 weeks after dipping as low as $3.64 per share at the height of the coronavirus market panic in March. LG Display shares are affordable in many ways. You can buy a single share for less than $10, and the stock trades at just 15 times forward earnings, or 0.7 times the company's book value.

The ultra-low book value ratio implies that the company could deliver more value to shareholders by shutting down the business, selling off its assets, and dividing its cash reserves among its owners. That idea is, of course, patently ridiculous, and I see the low price-to-book ratio as a strong signal to buy the stock today. LG Display's shares are incredibly undervalued right now.

United Microelectronics: $8.89 per share

Don't let the low stock price fool you. United Microelectronics (NYSE:UMC) is not a small business. The semiconductor manufacturing specialist sports a $21 billion market cap and $6.3 billion of trailing revenues. Both of these highly respectable numbers are only growing larger.

United Micro nearly doubled Wall Street's earnings expectations in each of its two latest quarterly reports. December's sales rose 14% year over year, inspiring two analysts to quietly raise their price targets for the stock. It's also hard to find a more effective cash machine than United Micro, which turned 39% of its incoming revenues into free cash flows over the last four quarters:

UMC Revenue (TTM) Chart

UMC Revenue (TTM = Trailing 12 month) data by YCharts

The company has achieved these impressive results by focusing on high-margin contracts with customers in explosive growth markets such as 5G networking, wireless earbuds, and driver circuits for OLED displays. Times were hard in 2018 and 2019, when the trade wars between Washington and Beijing took a heavy toll on United Micro's core markets. The company found effective workarounds in 2020 by focusing on Japanese and South Korean opportunities. The Taiwanese company is also boosting its production capacity across a wider geographic footprint by acquiring idle chip factories from Japanese peers Fujitsu and Toshiba.

This stock has more than tripled in 52 weeks and is trading at a nearly 20-year high, but the stock price still looks very reasonable at just 11.7 times free cash flows.

A bundle of fiber-optic network strands, lit up in white against a black backdrop.

Image source: Getty Images.

NeoPhotonics: $9.99 per share

Optoelectronic components are critical parts of fiber-optic networking systems, and fiber lasers allow manufacturers to perform high-precision cuts and welds. NeoPhotonics (NYSE:NPTN) makes components and modules in both of these categories.

This stock has been on fire sale since 2016 when the Trump administration blocked NeoPhotonics from doing business with Chinese electronics titan Huawei, its largest customer at the time. After trading sideways for five years, the stock is poised to bounce back in 2021.

"This is an exciting time for NeoPhotonics as we are seeing increases in design wins, backlog, higher volumes and resulting share gains in our highest speed over distance solutions with a broad range of customers, both historical customers and new customers," CEO Tim Jenks said in November's third-quarter earnings call. "Our strategy is to rapidly grow the business by supporting the highest speed over distance solutions at 400 gigabits and above for telecom equipment providers and expand our business by ramping our new 400ZR and 400ZR+ coherent modules to cloud and hyperscale data center customers starting in 2021."

This way, the company taps into the growing need for high-speed network lasers in the data center as well as in 5G wireless networks. As a leader in this deep and narrow niche, NeoPhotonics should post impressive growth on the top and bottom lines over the next couple of years. I don't expect the stock to stay in single-digit territory much longer. You can pick up NeoPhotonics shares from Wall Street's bargain bin at 9.4 times free cash flows and 1.2 times trailing sales. That's a steal.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.