Investing in stocks is a great way to build wealth. Yet no matter whether you're just getting started or have years of experience with the stock market, it can be scary to buy stocks -- especially when it seems like a new stock soars or crashes every day. Fortunately, you don't have to lose sleep at night to make money with stocks. Let's look at three great growth stocks that have already proven their mettle to early investors. They still have great prospects ahead, making them promising picks for investors who want strong long-term returns without the insomnia-causing drama. Image source: Getty Images. 1. Etsy 2020 was a tough year for many stocks, but it also thrust others into the spotlight. Etsy (NASDAQ: ETSY) answered the call by providing much-needed income opportunities for many people whose jobs were displaced by the COVID-19 pandemic. Forced to stay home from work, these budding entrepreneurs turned to Etsy's marketplace for arts, crafts, and other creative endeavors. As a result, Etsy's stock price quadrupled last year. Even though the company benefited from sales of face masks, Etsy isn't just another coronavirus stock play. Instead, the pandemic has simply been a catalyst for the online marketplace to distinguish itself from larger e-commerce plays like Amazon (NASDAQ: AMZN). Now, Etsy is taking what it's learned to implement valuable improvements, making its platform more attractive to the sellers who've discovered how lucrative being on the craft-focused marketplace can be. Etsy intends to add features like personalized search while expanding its marketing efforts to make its marketplace a go-to source for unique gifts. Bolstering its in-house tech expertise should also help Etsy keep up with growing traffic on its website. Between those efforts and prospects for international expansion, Etsy looks like it has a long growth runway ahead of it. 2. PayPal Holdings The rise of e-commerce during the pandemic has also made more people than ever familiar with electronic payments. That's played to the strengths of PayPal (NASDAQ: PYPL), which got its start working closely with an e-commerce marketplace partner before expanding to become a leader in payment network providers. PayPal has always been innovative, and it has high hopes for further new products this year. Potential offerings could include an investment platform, ways for users to spend money using cryptocurrency, and integration with shopping tool provider Honey, which PayPal acquired just over a year ago. Overall, PayPal is making a play to disrupt the way most people handle their finances, looking to offer a one-stop shop for just about everything related to money. Investors like what they've seen so far, and the stock has more than doubled in the past year. If PayPal can execute well on its current plans, further growth will come in the long run. 3. Apple Last but not least, Apple (NASDAQ: AAPL) has proven to be a much more tenacious growth stock than anyone ever imagined. Not content to stop when it hit the coveted milestone of $1 trillion in market capitalization, the iPhone maker went on to top the $2 trillion mark -- and it's still moving forward. Apple's prowess in the electronic device market is undisputed, with its smartphones, tablets, watches, and computers complementing its lineup of services and accessories to create a cash-cow business. Moreover, that business is in full growth mode right now, because the release of 5G wireless network technologies is forcing customers who don't want to be left behind to move forward with long-delayed upgrades to the new iPhone 12 smartphone lineup. Many investors counted Apple out when co-founder Steve Jobs died in 2011. Yet over the past decade, Apple has continued to soar, and its cutting-edge products have given the company a loyal fan base of customers who turn to it first for the latest and greatest technology. Apple's size and strength make it a stalwart holding in any investor's portfolio. Make money while you sleep Investing shouldn't keep you awake at night. The best stocks have strong business models that are easy for investors to understand and have confidence in. These three stocks look just about unstoppable right now, and they have promise that could lead them even further upward in the years to come. 10 stocks we like better than EtsyWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Etsy wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of November 20, 2020 John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Dan Caplinger owns shares of Apple. The Motley Fool owns shares of and recommends Amazon, Apple, Etsy, and PayPal Holdings and recommends the following options: long January 2022 $1920 calls on Amazon, short January 2022 $1940 calls on Amazon, and long January 2022 $75 calls on PayPal Holdings. The Motley Fool has a disclosure policy. Source