You have a choice in how to invest. You can try to play it relatively safe and only buy shares of well-known companies that have been around for a long time, or you can bet the farm on unproven stocks that might explode -- in a good way or bad.

Another path, though, is to invest in innovative companies that meet needs in new ways and are only in the early stages of targeting huge addressable markets. The good news is that you won't have to put a large amount of money upfront in these kinds of stocks. Their growth should turn even a relatively small initial investment into a big return over the long run.

If you've got $3,000 to invest, here are three game-changing stocks that you can buy right now.

Person looking up at illustrated light bulbs, one of which is illuminated.

Image source: Getty Images.

1. Teladoc Health

The COVID-19 pandemic has given many Americans their first taste of using telehealth services, and it's likely that telehealth will remain hot even after the pandemic is over. Teladoc Health (TDOC -0.75%) is in the best position to profit from this telehealth boom.

Scale is important for telehealth services providers in winning corporate and health plan customers. Teladoc ranks as the biggest telehealth company in the world. It offers the broadest range of services, with healthcare professionals spanning more than 450 medical subspecialties. 

Teladoc will soon add another service that's attractive to clients. The company expects to close its planned merger with Livongo Health (LVGO) later this year. Livongo's digital health management platform, which targets chronic diseases such as diabetes and hypertension, complements Teladoc's virtual care services well. 

The estimated addressable market for Teladoc and Livongo totals $121 billion in the U.S. alone. But the companies' combined revenue makes up less than 1% of this market. Teladoc Health appears to be well-positioned to capture a lot more of this market with the addition of Livongo. 

2. Sea Limited

My Motley Fool colleague Billy Duberstein recently referred to Sea Limited (SE -2.64%) as a "potential millionaire-maker stock." I think his description is spot-on.

Sea Limited focuses on three sizzling growth areas: online gaming, e-commerce, and digital payments. The company also targets fast-growing markets in Southeast Asia and Latin America.

Online gaming is Sea's biggest moneymaker. The company's Garena unit markets wildly popular games, including Free Fire, the most downloaded mobile game in the world last year. But its e-commerce and digital payments revenues are both growing quickly. Sea's Shopee ranks as the leading e-commerce platform in Southeast Asia and Taiwan. Its SeaMoney digital wallet is also picking up momentum, with more than $1.6 billion total payment volume in the second quarter. 

Sea has generated tremendous revenue growth in recent years, driving its share price up more than 1,000% since the beginning of 2018. However, the company should still have plenty of room to run in all of its product and geographical markets.

3. Innovative Industrial Properties

You might wonder how a real estate investment trust (REIT) could be viewed as a game-changer. Innovative Industrial Properties (IIPR -2.10%) has earned the distinction because of its impact on the medical cannabis industry.

Federal laws in the U.S. make it somewhat challenging for medical cannabis operators to raise the capital needed to fund expansion. IIP provides a solution to this challenge. The company buys properties from medical cannabis operators, then leases the properties back to the operators. These deals provide a steady revenue stream for IIP over a long period. Its weighted-average remaining lease term tops 16 years.

The cannabis-focused REIT has delivered impressive growth. Over the last three years, IIP's revenue has skyrocketed around 1,600%. Its share price has soared close to 680% during the period.

IIP shouldn't have a problem maintaining its momentum. The U.S. medical cannabis market is booming, with more states voting on legalization in November. IIP also offers another bonus for investors: Its dividend currently yields more than 3.8%.