Every investor should focus on holding a diversified mix of promising growth stocks. Getting rich in the stock market is simply a matter of patiently holding shares of growing companies over many years. Here are two easy-to-understand companies you can buy today that can deliver massive returns over the next 20 years.

1. Dutch Bros

The restaurant industry is easy to understand for most investors and has consistently produced winners over the last half-century. Dutch Bros (BROS -1.88%) was founded in 1992 and has grown to 982 locations with $1.3 billion in trailing revenue. And the stock is surging to new highs. The company continues to report solid financial performance as it expands across the U.S.

There seems to be a sizable opportunity for specialty beverage shops. Starbucks popularized fancy coffee, but new brands, like 7Brew and Dutch Bros, are taking it a step further with a menu centered on lemonade, energy drinks, smoothies, and others in addition to coffee.

The proof is in the numbers. Dutch Bros reported positive same-shop sales last year, even while Starbucks has experienced a notable decline in sales. In the fourth quarter, revenue grew 35% year over year, driven by 32 new shop openings and a 6.9% increase in same-shop sales. It plans to open another 160 shops this year.

While it continues to open new shops at a steady pace, Dutch Bros has also seen its margins steadily improve over the last year as it expands. It closed 2024 with adjusted net income of $88 million, up from $50 million in 2023.

Another reason Dutch Bros should be successful is that it promotes new shop managers from within the company. Someone can start out as a "broista" and eventually open and run a Dutch Bros location. This helps promote consistent service and instills a passion for the brand across the company.

Dutch Bros stock is positioned for a spectacular run over the next 20 years. It's only operating in 18 states so far, so it has great potential to open thousands of locations in the coming years.

2. Lululemon Athletica

The athleticwear industry is another ripe field to look for simple businesses that can produce wealth-building returns. Nike and Adidas are the leaders, but several new brands, many privately owned, emerged over the last 20 years or so, which speaks to the growing demand for activewear.

Lululemon Athletica (LULU -6.18%) has built an incredibly powerful brand that has grown from humble beginnings. In 1998, it started as a retail space in a yoga studio in Vancouver before opening its first stand-alone store in 2000. As of Oct. 27, 2024, it had 749 company-operated stores worldwide, with 39% of revenue coming through online sales.

Lululemon's revenue grew close to 20% per year over the last decade, with earnings growing slightly faster. The company still has ample room to expand worldwide.

Revenue from the Americas region made up 74% of the business in the fiscal third quarter, which leaves a lot of room for growth in Europe and China.

Lululemon has experienced tremendous growth in China, with fiscal third-quarter comparable sales, which measures the performance at stores open at least 12 months, up 27%. China's growing middle class will be a major opportunity for Lululemon's premium brand. Management sees international revenue coming into a 50-50 balance with North American markets over the long term.

Lululemon also has a huge opportunity to win more business from men. Women's products generated over $1.5 billion in revenue in fiscal Q3, 65% of the company's total revenue. But the brand's high customer satisfaction scores across all categories show great potential to balance its appeal between men and women.

The stock trades at a reasonable valuation of around 26 times this year's earnings estimate. Lululemon stock climbed 500% over the last 10 years and should continue to grow in value over the next decade and beyond.