The Nasdaq is home to many of the best growth stocks in the world. Some of them have generated life-changing returns for investors, including Apple (AAPL 0.50%)Nvidia (NVDA 1.69%), and Idexx Laboratories (IDXX -1.21%). These stocks have all been 10-baggers over the past decade. Here's a closer look at these companies and whether they are still excellent investments today.

1. Apple

In 10 years, shares of tech giant Apple have risen by more than 1,000%. If you'd invested only $10,000 in June 2013, it would be worth around $113,600 today. And that's investing at a time when Apple was already a big tech company known for its iPhones and growing ecosystem. Today, the company has a variety of different services, including music, streaming, books, news, and many others.

Apple hasn't run out of ideas to grow, either. This month it unveiled Vision Pro, the company's augmented reality headset. Healthcare is another potential area of long-term growth for the business, as there have been rumors the company could be adding a blood glucose monitor on a future iteration of its Apple Watch.

A company like Apple that gushes profits and free cash flow can afford to spend money on various ventures to see which one pays off. In the trailing 12 months, the company's free cash flow totaled more than $97 billion.

That's why, despite being nearly worth $3 trillion, it may still not be too late to buy this behemoth, as Apple could have more growth opportunities to pursue in the future. At 28 times earnings, the growth stock isn't cheap -- but it's still not a big premium to own shares of a company that billionaire investor Warren Buffett says is "probably the best business I know in the world."

2. Nvidia

Nvidia recently hit the $1 trillion valuation mark, as its stock has been rising sharply this year. Known for its video cards, Nvidia is a top name in computing, and the emergence of chatbot ChatGPT has only enhanced its popularity with investors. 

Artificial intelligence (AI) is the next new growth area for the business, with Nvidia recently launching an AI platform that it says offers "full-stack innovation in computing, software, and AI models and services." Nvidia's chips can also help companies build out their AI capabilities.

The company forecast that for the current quarter (which ends in July), its sales will be around $11 billion -- smashing analyst expectations of $7.2 billion, leading to a rally in the stock's valuation. Demand has also been red hot for its data center products, fueling the company's strong numbers.

Although its valuation has gone through the roof, with Nvidia's stock now trading at more than 80 times estimated future profits, it still has more upside to go as it promises to be a big name in AI.

In 10 years, its shares have jumped by more than 10,000%, and a $10,000 investment a decade ago would be worth close to $1.1 million today. And remarkably, it may still make for a great long-term buy right now.

3. Idexx Laboratories

Pet healthcare company Idexx Laboratories has given back some gains over the past few years, but its 10-year returns sit at just over 1,000%. A $10,000 investment in the stock a decade ago would now be worth around $107,000.

The company has customers in over 175 countries, giving the business plenty of growth opportunities. Unlike the fast-growing tech and consumer stocks up higher on this list, Idexx's growth has been more constant and steady over the years:

IDXX Revenue (Annual) Chart
IDXX Revenue (Annual) data by YCharts.

In 2023, for example, it's projecting revenue growth between 7.5% and 10%. On the bottom line, however, it's projecting up to 22% growth in earnings per share.

The bulk of the company's revenue (approximately 92%) comes from the companion animal group segment, which includes veterinarian diagnostics products and services for pets. It also generates revenue from water testing products and livestock and poultry diagnostics.

Spending on pets has risen over the years, ensuring demand for Idexx's products and services continues to increase. According to the American Pet Products Association, the U.S. pet market was worth $136.8 billion in 2022, representing a 51% increase from $90.5 billion in 2018. And this year it expects the market to rise to a value of $143.6 billion.

With more spending still on the way, Idexx's business will remain strong. One obstacle that may keep investors from buying shares of Idexx, however, is the stock's hefty earnings multiple of around 60. Given the more modest growth opportunities in this industry, it may be hard to justify such a valuation for Idexx.