When it comes to investing in growth stocks, a long-term mindset can be a lucrative advantage. Peering further into the future can enable you to position your portfolio for fortune-building gains. Here are two businesses with excellent long-term expansion prospects that could make you richer in the coming years.

Growth stock to buy No. 1: Eli Lilly

Millions of people around the world want to look and feel better. Eli Lilly's (LLY -1.38%) blockbuster new weight-loss drug is helping people do that and more while delivering hefty profits to investors.

Zepbound, the healthcare giant's weight-management treatment for adults, could be a game changer for the nearly 70% of American adults who are obese or overweight. These weight-related conditions put people at higher risk for diseases like diabetes, heart disease, and strokes.

Zepbound makes it easier to eat less food by curbing hunger. A 72-week clinical study showed that people who took the highest dose of the drug shed an average of 48 pounds. Tirzepatide, the active ingredient in Zepbound, has also been shown to improve cholesterol, blood pressure, and blood sugar levels in adults.

With so many potential benefits, sales of Zepbound are set to soar. Goldman Sachs predicts that Eli Lilly will capture the lion's share of an obesity drug market that could reach $130 billion by 2030. Analysts, in turn, expect Eli Lilly to grow its earnings per share by a stunning 63% annually over the next five years.

Growth stock to buy No. 2: Tesla

Tesla (TSLA -4.95%) is another top-tier company with leading positions in booming markets. The electric vehicle (EV) leader also has intriguing expansion potential in artificial intelligence (AI) and robotics.

The EV industry will top $950 billion by the end of the decade, up from roughly $388 billion in 2023, according to research firm MarketsandMarkets. Tesla clearly still has a long runway for growth in its core EV segment.

Tesla is also a frontrunner in the autonomous vehicle race. Cutting-edge AI powers its rapidly improving self-driving technology. With millions of vehicles on the road, the EV pioneer has a powerful data-collection advantage over rivals like Alphabet's Waymo. Tesla's Autopilot software is thus in a strong position to achieve full self-driving capabilities before its competitors.

CEO Elon Musk wants to use this technology to build a fleet of robotaxis. Tesla is developing a new autonomous vehicle dubbed Cybercab as part of its ambitious plan to revolutionize the ride-hailing industry. Cathie Wood's Ark Invest estimates that Tesla's driverless car initiative could produce revenue of more than $600 billion by 2029 -- and drive its stock price up tenfold to $2,600 per share by that time.

Incredibly, Tesla may have an even more potent growth driver in AI-powered robots. The tech titan is building a sci-fi-like humanoid robot called Optimus. Tesla's bot is intended to bolster productivity and ease labor shortages in factories and other settings by taking on tasks that are dangerous or monotonous for humans. Musk sees an enormous array of possible use cases for the company's robots. So many, in fact, that he pegs Tesla's long-term profit opportunity at a staggering $1 trillion.