Going big doesn't mean you have to sacrifice growth. It's a common misconception that to find millionaire-making stocks you have to invest in small growth companies, but that's not necessarily the case. 

There are plenty of large-cap stocks that are growing fast and could multiply your initial investment over time. Here's why Nintendo (OTC:NTDOY), Square (NYSE:SQ), and Uber Technologies (NYSE:UBER) could fit the bill.

A pile of one hundred dollar bills

Image source: Getty Images.

Nintendo: Growing digital sales

If you bought shares of Nintendo in January 2017, a few months before the Switch console launched, you would have already doubled your money. The Switch has been a boon for the Japanese gaming giant, with 41.67 million units sold through the end of September. Trading at a price-to-earnings ratio of 34, the stock is not cheap, but there are good reasons investors are paying a premium for the shares right now. 

The stock is not likely going to move higher from here based on more sales of Switch consoles. Despite continued strong sales of the game system over the last year, including the launch of the Switch Lite, full-year sales are only expected to increase by 4.1% this fiscal year (which ends in March). The system is selling well, just not enough to fuel incremental growth on the top line.

From here, the stock could head higher based on improving margins and growing profits. More of Nintendo's software sales are coming from digital sales, including full-game downloads, Switch Online subscriptions, and add-on content for games, but at just 36% of sales, Nintendo's percentage of game sales that come from digital channels is much lower than other game makers such as Electronic ArtsActivision Blizzard, and Take-Two Interactive. Those companies generate about three-quarters of their revenue from digitally delivered content, much higher than Nintendo.

Another catalyst for the stock could be stronger-than-expected sales of the Switch in China. However, analysts are not expecting big numbers because Chinese players have historically not been interested in playing on console game systems. 

Still, Nintendo's partnership with Tencent to launch the hardware in China could pay off. Nintendo has exclusive gaming brands you can't play on anything else but Switch, and Tencent has a strong marketing pull with more than one billion users across its social media apps, QQ, and WeChat. 

All in all, Nintendo is a classic gaming brand, with a growing installed base of Switch owners who will likely spend more money on games over the next year. Throw on top of that Nintendo's increasing push into mobile games, in which its recent Mario Kart Tour has performed well, and the stock should remain a good investment even at these elevated levels.

Square: Improving profit margins

For Square, it's been a seesaw battle between the bulls and the bears over the last year. On one hand, revenue growth remains robust, coming in at 44% year over year in the third quarter. That was good enough for the company to raise its full-year guidance. On the other hand, it's been difficult for investors to get a handle on Square's lack of profitability; the company continues to plow everything back into future growth -- although that's not a bad thing if you have a long-term mindset.

Square's investments in seller tools for merchants earn a quick payback on investment within about four quarters. The seller ecosystem is on pace to earn an adjusted (non-GAAP) EBITDA (earnings before taxes, interest, depreciation, and amortization expense) margin of nearly 30% this year. 

With that much profitability in the core business, management is shifting resources to double down on investments in the seller ecosystem. Square just sold the Caviar restaurant ordering platform and is now ramping up its investment in performance marketing to educate business owners about the Square product offering and expand its user base. Since April, key metrics like awareness, web traffic, and revenue contribution have been higher since management initiated a new marketing campaign. 

Another key aspect to Square's future growth is the Cash App -- one of the most widely used peer-to-peer payment apps. Square is continuing to expand the ways individuals can engage and use the app as a daily cash utility tool. The latest move is to allow Cash App users to trade fractional shares of stocks. This opens the door for even more people to join the app and take advantage of the all-in-one solution Square is providing for everyday finances. Excluding bitcoin transactions, the Cash App generated revenue of $159 million in the third quarter, more than doubling year over year. It's not generating a profit yet, but further top-line growth like this will eventually put the Cash App in the green as scale kicks in. 

The broad capabilities Square has across seller software services, point-of-sale solutions for businesses, and long-term upside with the Cash App are why investors should consider buying the stock -- before better news sends the shares higher.

A woman holding a smartphone getting into a car

Image source: Uber Technologies.

Uber: The transportation disruptor

Uber has been a controversial stock since its IPO. Investors are skeptical about its path to profitability and concerned about slowing growth in recent quarters. Moreover, the company has wrestled with ethics concerns in its corporate culture. But with the co-founder and former CEO severing ties with the company by selling 100% of his shares recently, investor sentiment should gradually shift more positive, as the ride-sharing company has plenty going for it.

Concerns about slowing revenue growth abated last quarter as Uber reported an acceleration on the top line. Adjusted revenue grew 33% year over year, which is a significant improvement over 12% growth in the second quarter. More importantly, the Rides segment saw a significant jump in adjusted EBITDA, reaching 5% of gross bookings. 

Companywide, Uber is still not generating a profit, with total adjusted EBITDA margin at negative 3.6% last quarter, although that is an improvement from the negative 5.9% in the first quarter. One segment weighing on profitability is Uber Eats: the market for food delivery is very competitive. Competitors have been relying on free delivery promotions and discounts to win customers, and that makes it hard for Uber to run its business profitably.   

However, management mentioned on its third-quarter conference call that it's starting to see signs of "rationalization" in the delivery market, which has already been taking place in Rides. Managers across the company are going line by line to cut excessive costs to improve profit margins, as CEO Dara Khosrowshahi explained on the call. This contributed to the improved EBITDA margin in Rides last quarter, and now management is looking to do the same with Eats. Overall, management believes the company will achieve breakeven by 2021. 

Uber faces plenty of competition, including rival Lyft and local ride services worldwide. But Uber has the advantage of scale to win in the marketplace. Uber currently generates $13 billion in annual revenue, and that provides management with plenty of resources to invest in technology and features that smaller players can't compete with. 

Regulation is also a risk to watch. California and New York have passed laws impacting the employment status and hourly pay for drivers. Despite these concerns, I believe Uber is worth at least a small position in your nest egg because it's playing the role of disruptor in the global transportation sector.

The long-term upside is simply too big to ignore, especially if Uber discovers additional business lines in the future where it can effectively apply its technology and expand its addressable market.