This year has certainly been one for the record books, with investors experiencing both a record stock market plunge and a record recovery, all in the span of several months. The screaming stock bargains that were available in late March didn't last for long, and investors who hesitated may feel they missed the boat.

Fortunately, for investors with a keen eye, a stomach for an element of risk, and a sufficiently long investing timeline, there are still opportunities to boost your long-term returns by adding some high-growth stocks into the mix.

If you have $4,000 (or less) in disposable cash to invest that you don't need for immediate expenses or to supplement your emergency fund, putting it to work in these four stocks could just make you rich.

Excited woman scattering hundred dollar bills.

Image source: Getty Images.

1. Teladoc and 2: Livongo: A healthy two-for-one sale

There's little doubt that Teladoc Health (TDOC -4.54%) and Livongo Health (LVGO), with their ties to connected instruments and telehealth, have been on fire this year as the result of the stay-at-home orders resulting from the coronavirus pandemic. Patients young and old have done their level best to avoid trips to the doctor's office for fear of contracting COVID-19.

The ability to serve patients remotely has served these companies well. For its second quarter, Teladoc reported revenue that grew 85% year over year and total patient visits that soared 203%. For the first six months of 2020, revenue climbed 63% and visits jumped 144%. 

Livongo Health fared similarly well, with second-quarter revenue up 125% year over year, while patients enrolled in its flagship program -- Livongo for Diabetes -- climbed 113%. That was after 115% revenue growth and patient growth of 100% in the first quarter. 

Through the beginning of this month, these factors helped drive Teladoc's shares up nearly 200% year to date, while Livongo's soared more than 475%.

Investors seemed to completely dismiss these robust results and the potential for future gains when the two providers announced in early August that they would merge, creating a "new standard in global healthcare delivery, access, and experience." In the wake of last week's announcement, shares of Livongo and Teladoc have plunged 20% and 26%, respectively, thus far. 

The stock market's reaction defies logic. It isn't as if growth will simply dry up as a result of the merger. These are two high-growth companies that will be able to make deeper inroads in the connected health market, with specialties that are completely complimentary.

Of course, there's always the potential that conflicting management styles or corporate cultures could derail a successful integration, but assuming that's going to happen is a leap too far. I expect the combined company will continue to be hugely successful, and investors who add now will be very glad they did.

Man working in network server room, plugging cords into the backs of servers.

Image source: Getty Images.

3. DataDog: Take this puppy for a walk

The pivot to cloud computing was already in full swing, but in the face of the pandemic, the shift accelerated into high gear, as remote work became the rule rather than the exception. It also became more important than ever that cloud-based systems were ready to meet the increased demands of a distributed workforce, with the ability to identify problems before they became critical issues, resulting in unnecessary downtime.

That's what DataDog (DDOG 0.80%) brings to the table. The cloud-native analytics provider monitors servers, databases, tools, and services, using artificial intelligence to detect anomalies, providing near-real-time information about problems as they occur, to keep them from becoming even bigger issues. Once the snag has been resolved, DataDog provides helpful analytics that can be used to help keep the problem from recurring.

DataDog reported robust results for the second quarter, with revenue that grew 68% year over year, down slightly from 87% gains in the first quarter. Customers bringing in annual revenue in excess of $100,000 grew to 1,015, up nearly 71% year over year.

The company continues to garner industry accolades that attest to its stature. DataDog was recognized as a 2020 Gartner Peer Insights Customers' Choice for IT Infrastructure Monitoring Tools, receiving 4.5 out of 5.0 stars from IT professionals who use its products.

Management is guiding for 50% year-over-year revenue gains in the third quarter, a deceleration from its recent torrid growth, which no doubt contributed to the markets' tepid reception of its recent results. Given DataDog's historic practice of issuing conservative guidance, only to easily surpass its forecast, this move isn't entirely unexpected. However, bargain hunters can now get the stock for a 20% discount to recent highs.

Woman on a laptop using DocuSign.

Image source: DocuSign.

4. DocuSign: (E) Sign here for revenue growth

Another company that's gotten a shot in the arm from the need for remote work and social distancing is DocuSign (DOCU -0.59%). The provider of electronic signatures was already the undisputed leader, with about 70% of the e-signature market, but the new reality requiring deals to be sealed remotely gave the company a sizable advantage. 

DocuSign reported first-quarter revenue that grew 39%, matching its growth rate from 2019. The company has keen insight into its future revenue, as nearly 95% of its revenue came from subscriptions, providing a solid base of recurring income that typically isn't subject to fluctuation. At the same time, DocuSign's adjusted profits climbed 71%. 

The company has another revenue stream that's sure to grow in importance in the coming years. Early last year, DocuSign introduced the Agreement Cloud, a suite of products and integrations that help automate the entire life-cycle of contracts, creating a digital process to prepare, sign, act on, and manage agreements. 

Even as the leader, the e-signature market is still in the early stages. Management estimates the potential market at $25 billion, and with just $974 million in revenue last year, DocuSign still has a massive opportunity -- and that doesn't count another $25 billion market opportunity for the Agreement Cloud, giving the company a long runway ahead. 

Yet, the recent rotation out of high-flyers has sent DocuSign's stock down more than 15%, with no company-specific news driving the decline. This means that forward-looking investors can get the stock at a discount to recent highs, with no change in the thesis.

TDOC Chart

Data by YCharts

Every rose has its thorns

Each of the companies highlighted above has the potential to be a multi-bagger, returning many times its original investment, which is what you'd expect from a high-risk, high-reward stock. That said, eagle-eyed investors will also have detected that in addition to their high-flying status, these stocks share another common trait -- their expensive valuations.

Teladoc and Livongo Health are currently valued at 15 and 32 times forward sales, respectively, when a good price-to-sales ratio is generally considered to be between one and two. DataDog and DocuSign are equally pricey, with forward valuations of 40 and 26, respectively. In each case, however, investors have thus far been willing to pay up for the impressive top-line growth and the potential for future success.

Past performance is no guarantee of future success, but given the results these growth stocks have achieved so far this year, if they continue on their current trajectory, they could just make investors rich.