If you thought investing during the coronavirus disease 2019 (COVID-19) crash was interesting, 2021 has been one big hold-my-beer moment. For much of the past three weeks, Wall Street and the investment community have stood back and marveled at the Reddit-fueled retail-investor rally, which has led to historic volatility in brand-name stocks like GameStop (GME 1.50%) and AMC Entertainment (AMC -0.88%). In January alone, GameStop and AMC logged respective gains of more than 1,600% and 500%.

Without digging too far into the weeds, retail investors on Reddit's WallStreetBets chatroom agreed to band together to buy into stocks that were heavily sold short. Short-sellers are investors (mostly hedge funds and investment banks) who make money when the price of a security falls. Gains are capped at 100%, but losses are unlimited for short-sellers.

By purchasing shares and out-of-the-money calls on GameStop and AMC, these retail investors triggered a short squeeze. Essentially, it sent short-sellers scurrying for the exit all at once, causing both companies' share prices to spike higher.

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While this has been amazing to watch, it's also incredibly dangerous for investors. The speculation and potential price manipulation we've witnessed in GameStop and AMC Entertainment will almost certainly result in both companies retracing the bulk of their gains.

What's more, it's not as if either company is in great financial shape. Video game and accessories retailer GameStop was late to the party when it came to switching over to digital downloads, and it's lost money in each of the past three years. Meanwhile, AMC narrowly avoided bankruptcy a few weeks ago and might be seeing its entire operating model disrupted by the likes of WarnerMedia, which is streaming all of its movies in 2021 at the same time that they're released in theaters.

My suggestion is to completely forget about AMC and GameStop and focus your attention on growth stocks that could put some legitimate and sustainable pep into your portfolio. The following four growth stocks could all triple in value, and they make for much smarter investments than AMC or GameStop.

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CrowdStrike Holdings

If you want highly sustainable, transparent growth, look no further than the cybersecurity industry and CrowdStrike Holdings (CRWD 3.63%). With more businesses than ever creating an online presence and moving their data into the cloud, the onus of protecting this information is falling on third-party providers like CrowdStrike.

What allows CrowdStrike to really stand out is the company's cloud-native Falcon security platform. Falcon relies on artificial intelligence and oversees more than 3 trillion (yes, with a t) events each week. This is a fancy way of saying that the more customers CrowdStrike enrolls, the better its cloud-based platform becomes at identifying and responding to threats. Since it was built in the cloud, it's response time often beats its competitors, and it's actually cheaper than running on-premises security solutions.

But the proof is in the pudding -- and by "pudding," I mean the company's operating results. During the fiscal third quarter, CrowdStrike noted that 61% of its customers had at least four cloud-module subscriptions. That's up from 9% just 3 1/2 years earlier. What this suggests is that CrowdStrike's platform is easily scalable and growing right alongside its clients.

Having already reached its long-term subscription gross margin target, CrowdStrike looks like a beast of a stock to own.

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Lovesac

Sometimes, the tiny tots can offer the most robust reward to patient investors. That's why modular furniture and accessories designer Lovesac (LOVE 0.55%) is a company that growth investors can buy and hold with confidence.

Lovesac predominantly targets millennial consumers in the 35 to 39 age range, with choice and eco-friendliness acting as its lures. Just over 80% of the company's sales are derived from sactionals -- a sectional-style couch that can be rearranged numerous ways to fit any livable space. These sactionals come with over 250 different cover choices that are machine washable and easy to swap out. Further, the yarn used in sactionals is made entirely from recycled water bottles. I'm talking to you, ESG investors.

But what sets Lovesac apart in the relatively stodgy furniture industry is its low overhead and ability to adapt to any economic environment. Since it's catering to a more digital-friendly generation of shoppers, it pivoted away from physical and pop-up showrooms in 2020 and pushed most of its products online. This helped lower inventory costs even more, resulting in the company pushing toward profitability ahead of schedule.

With a market cap of only $810 million and an operating model hell-bent on disrupting the furniture space, Lovesac looks to have a real shot a tripling in value.

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Cresco Labs

Marijuana will likely be one of the fastest-growing industries this decade, with no market in the world expected to generate the green quite like the United States. That's why multistate operator (MSOs) Cresco Labs (CRLBF 1.51%) still looks like one heck of a bargain.

Like most MSOs, Cresco has a retail presence that's likely to get bigger. It has 20 operational dispensaries at the moment, 10 of which are in the limited-license state of Illinois. Having opened its doors to recreational pot on Jan. 1, 2020, Illinois managed to surpass $1 billion in combined weed sales (medical plus adult-use) in its first year. Cresco is also in the process of acquiring Bluma Wellness, which'll give the company a healthy retail presence in Florida.

The more intriguing opportunity for Cresco Labs comes from its wholesale operations. Although wholesale cannabis produces lower margins than retail, Cresco has more-than-enough volume to make up for these lower margins. That's because it acquired Origin House in an all-stock deal in January 2020, which gave it access to Origin's highly coveted cannabis-distribution license in California. Being able to place its pot products into more than 575 dispensaries in the Golden State should make this company a money machine.

Look for Cresco to officially turn the corner to recurring profitability this year.

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Sea Limited

Another growth stock that can triple in value and run circles around AMC and GameStop is Singapore-based Sea Limited (SE 4.34%). Sea might be incredibly expensive on a fundamental basis, but all three of its operating segments are growing at a lightning-fast pace.

For the time being, Sea's gaming arena segment is its biggest generator of positive adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA). As of the end of September, the company had more than 572 million active users, 65.3 million of which were paying customers. With the pandemic keeping people in their households, quarterly paying users have been rising at a much faster pace than total gaming users.

However, the long-term potential of online marketplace Shopee is why most folks are buying into the Sea Limited growth story. Southeastern Asia has a burgeoning middle class, and Shopee should be a direct winner of this middle class putting their disposable income to work. In the September-ended quarter alone, gross merchandise revenue doubled from the prior-year period to $9.3 billion -- and we're still in the very early innings of e-commerce growth in Southeastern Asia. 

Sea's third operating segment is digital financial services. Considering that parts of Southeastern Asia are underbanked, the digital wallets Sea provides could be a financial services game changer for the region.

Given time, Sea Limited can easily triple from its current market cap.

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.