Growth stocks can fall with the broader market, but the best ones can outperform over many years. History shows that time in the market is a better -- and much easier -- path to building wealth than trying to time the market. You only need to buy shares of a growing business and remain patient.

If you have a few hundred dollars to spare, there are some promising growth stocks that could multiply your money in the years to come. Here's why you might want to consider buying a share of Tesla (TSLA 3.23%) and C3.ai (AI -0.27%).

Tesla: Invest alongside a visionary billionaire

Investors who were fortunate enough to buy into billionaire Elon Musk's vision for electric cars in 2012 would be much closer to an early retirement. A $1,000 investment would be worth around $90,000 now.

Tesla's magnificent returns over the last 10 years show why you only have to be right once about a great growth stock to offset countless mistakes in investing. By 2018, Tesla stock had already generated a nearly tenfold return from 2012, but investors who doubted its growth opportunity would have missed out on another 800% increase over the last five years. Tesla's ability to deliver market-thumping returns is far from over.

There are about 85 million light vehicle sales per year in the global auto industry, and that figure has grown from 55 million over the last 20 years. Electric cars are only a fraction of that total but are gaining share fast. Tesla is on track to deliver just 1.8 million cars this year. 

Tesla still has plenty of room to grow, and that means the stock can still hit new highs for many years. In fact, I don't think we've seen the company's best yet. The upcoming Cybertruck could become one of the top-selling electric vehicles, with more than 1 million people already on the reservation list. 

Tesla is having to literally break the mold to bring Cybertruck to market. The unique design of the truck is exactly why you should consider buying the stock. The truck's exoskeleton is stainless steel, which forced Tesla's engineers to create new manufacturing processes to make the vehicle. Unlike other car companies, Tesla is willing to take risks and try new things, and that explains a lot of its success.

Investors will have to brace for some bumps in the road, especially with rising interest rates making it more expensive to buy new cars, but any dip in the stock would present a great chance to buy shares at better value points.

Tesla is investing heavily in artificial intelligence (AI) software to fulfill Musk's goal of making its cars fully autonomous one day, and that could open a huge opportunity in robotaxis and other arenas in the transportation sector. 

C3.ai: A small software business on the cusp of a breakout

AI software specialist C3.ai could be a home run stock in the making, but the shares have underperformed since its initial public offering a few years ago. C3 is a relatively small software company that is unprofitable and not delivering enough revenue growth yet to justify the stock's high valuation. Despite those issues, shares have more than doubled year to date, and it could be just getting started at capturing a large piece of the booming AI software market. 

C3 is gaining momentum in signing new deals with major customers, including the U.S. government. Companies are turning to AI software to solve complicated business problems.

In the most recent quarter, C3 entered new agreements with Tyson Foods, Shell, Saudi Arabia's smart city, and the U.S. Department of Defense, among other major organizations. Federal bookings were up 39% year over year last quarter, which is a strong indication of the effectiveness of C3's technology. 

Like the Musk factor at Tesla, a great reason to consider buying C3.ai shares is the leadership. CEO Thomas Siebel has a record of delivering growth in the software industry. He founded sales automation company Siebel Systems in 1993, which was sold to Oracle for $5.8 billion in 2005. 

Siebel knows how to identify opportunities that others miss. At the time he founded C3.ai in 2009, the AI software market didn't really exist. Now it's on pace to become a $667 billion industry by 2030, according to Fortune Business Insights. 

Investors have an opportunity to buy the stock while it's still on the ground floor, trading about 85% off its previous high. One reason for the stock's underperformance is that analysts expect full-year revenue to increase by just 15% this year. Moreover, C3 will also need to boost its bottom line after reporting a net loss of $64 million last quarter on $72 million of revenue.  

However, as more companies learn how to use AI, C3 could see accelerating growth and improving profitability over the next few years. The business generates nearly all of its revenue from subscriptions, and it recently adopted a consumption-based pricing model.  This means as customers use the software more, it should drive higher utilization fees and profits.

Considering its impressive roster of clients, massive opportunity, and Siebel's previous success in building a multibillion-dollar software business, this is a promising growth stock to hold for the next 10 years and beyond.