This has proved to be one of the wildest years on record for Wall Street -- and there are still more than four months to go. Panic and uncertainty originating with the coronavirus disease 2019 (COVID-19) pandemic initially pushed the broad-based S&P 500 lower by 34% in a mere 33 calendar days. But over the subsequent five months, the benchmark index has gained virtually everything back.

Though it's unclear where the stock market may head next, with volatility quite normal following a bear market bottom, one strong likelihood is that growth stocks will outperform. With the Federal Reserve pledging to keep lending rates low through 2022, the table is set for high-growth companies to borrow cheaply and expand quickly.

Best of all, you don't need to a have a fortune to make one on Wall Street. If you have, say, $5,000 you can spare that won't be needed for bills or emergencies, then you have more than enough to buy four of the fastest-growing stocks on Wall Street right now.

A businessman in a suit holding a potted plant in the shape of a dollar sign.

Image source: Getty Images.

Livongo Health & Teladoc Health

The first two fast-growing stocks I'm going to lump together for a very logical reason -- they're merging.

On one side of the coin is Teladoc Health (NYSE:TDOC), the largest telemedicine company in the country. Telemedicine was already taking off well before COVID-19 came into the picture. However, with physicians wanting to keep potentially infected patients and high-risk/chronic disease patients out of offices and hospitals, telemedicine visits for both subscribing members and fee-only visits for non-members have skyrocketed.

Teladoc's second-quarter operating results featured a 209% increase in visit-fee revenue and a 78% jump in sales from the United States. All told, visits more than tripled to 2.8 million during the quarter. Insurers are bound to love this since telemedicine visits are often cheaper than in-office visits. This makes it increasingly likely that telemedicine visits will be promoted by health-benefit providers moving forward. 

On the other side of the coin is healthcare-solutions provider Livongo Health (NASDAQ:LVGO). Livongo aggregates mountains of data from its members with chronic illnesses and uses artificial intelligence to send people tips and nudges to induce lasting behavioral changes. Staying on top of a chronic disease like diabetes can often be half the battle, and Livongo aims to help patients win that fight.

Livongo has consistently been doubling (or more than doubling) its diabetes member patient count over the past couple of years, reaching over 416,000 members by the end of June. Still, this only represents 1.2% penetration of the U.S. diabetes market (34.2 million people). With Livongo expanding its solutions into new indications, such as hypertension and weight control management, the company's patient pool is going to expand dramatically. 

With Teladoc "merging" with Livongo in a cash-and-stock deal, investors don't have to be choosy when it comes to these fast-growing healthcare stocks of the future.

An up-close view of a flowering cannabis plant in a commercial indoor grow farm.

Image source: Getty Images.

Innovative Industrial Properties

If you have $5,000 at the ready, you can also consider buying into one of the hottest growth trends of the decade: marijuana.

Though it's no secret that the U.S. is the premier global cannabis market, it's unclear which pot stocks will emerge as winners in the early stage of the industry's expansion. But that's not really a concern if you choose to buy marijuana-focused real estate investment trust (REIT) Innovative Industrial Properties (NYSE:IIPR).

Like any REIT, Innovative Industrial Properties is seeking to acquire assets that can be leased out for an extended period of time. In its case, it's acquiring marijuana cultivation and processing facilities. Since the beginning of 2019, the company has bought 50 properties, upping its portfolio to 61 properties in 16 states. 

The beauty of the marijuana REIT model is twofold. First, it's a low-cost operating model that results in big dividends for shareholders. Beyond the initial cost to acquire a property, maintenance and administrative costs remain low.

Secondly, it's a highly profitable model with a transparent outlook. The company's 61 properties had a weighted-average lease length of 16.1 years as of early August, with its last reported average yield on invested assets from the first quarter of 2020 being north of 13%. This suggests the company could recoup its investment capital in roughly six years but will see recurring revenue from its leases for 10 years longer than that. Not surprisingly, Innovative Industrial Properties is the most profitable pure-play pot stock on a per-share basis.

With U.S. marijuana sales expected to potentially triple between 2019 and 2024, IIP is in the driver's seat to benefit as a lessor of cultivation and processing sites.

A man holding a Shopee bag, with his happy woman next to him.

Image source: Sea Limited.

Sea Limited

Another one of the fastest-growing stocks on the planet you can consider buying right now with $5,000 is Singapore-based Sea Limited (NYSE:SE).

There's no denying that Sea comes with a hefty premium. Shares of the company have tripled on a year-to-date basis, tacking on roughly $40 billion in market cap, even though the company is losing money on an annual basis. But a quick glimpse at how the company's three operating segments have fared during the pandemic shed light on why Wall Street and investors are so bullish.

For the time being, Sea's bread-and-butter segment continues to be digital entertainment. The company's mobile game Free Fire hit a peak of 80 million daily active users during the first quarter and was largely responsible for helping to push adjusted segment revenue up 30% in Q1 2020. Adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) for digital entertainment rose 32% to $298.4 million.

The second operating segment is where the real buzz lies: e-commerce. The company's Shopee platform, which was built from the ground up, is targeting a burgeoning middle class in Southeast Asia. Keep in mind that local economies have been disrupted by COVID-19 in Southeast Asia, as they have in the U.S., meaning consumers are leaning toward online purchases now more than ever. Not surprisingly, gross merchandise value crossing Shopee's platform surged 74% during Q1 2020 to reach $6.2 billion. 

Lastly, Sea has expanded into digital financial services. With more and more consumers spurning cash during the pandemic for digital wallets, it's no shock to see digital financial service revenue rapidly rising.

While it's possible Sea Limited's stock could take a breather after tripling in under eight months, the future looks incredibly bright for Shopee and its digital financial services.

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.