Canopy Growth (NYSE:CGC) has already made some investors quite rich. Since the company's initial public offering in 2014, Canopy stock has skyrocketed around 1,380%. Along the way, Canopy Growth became the world's largest marijuana business in terms of market cap.

But will Canopy Growth make investors who buy the stock now wealthy, too? Could it even be a millionaire-maker stock? Here's what it would take.

Man in a suit holding an umbrella with money raining down

Image source: Getty Images.

Two very different challenges

First of all, for Canopy Growth to make current investors rich is a much different challenge from making current investors millionaires. Both are possible. But one is much more probable.

Of course, how much money makes a person wealthy is subjective. What you thought was wealthy when you were a teenager probably doesn't match up with what you think is wealthy now. What your friend who lives in an area with a low cost of living thinks is rich will probably differ from what a friend who lives in an area with a high cost of living thinks.

That being said, a stock that performs well can certainly make an investor significantly richer than when they bought the stock. If that's our criteria, then it wouldn't be terribly difficult for Canopy Growth to make investors who buy shares now rich -- relatively speaking.

However, for Canopy Growth to be a millionaire-maker stock for most investors is a tall order. And we're talking about a Mount Everest kind of tall.

Important variables

The key factor in answering our initial questions is just how much Canopy Growth can grow. Those growth prospects depend on several important variables.

One important variable is whether or not the U.S. legalizes marijuana at the federal level. Currently, the U.S. represents around 85% of the worldwide legal marijuana market. Even as marijuana markets expand in other countries, the U.S. appears likely to generate at least three-quarters of total global marijuana sales for years to come.

Another critical variable is how quickly legal marijuana markets displace the illicit black market for marijuana. Some executives of marijuana companies like to talk about a global marijuana market of $150 billion or more. However, this figure is largely made up of illegal marijuana sales. Even when marijuana is legalized, the black market can still thrive -- something California found out last year. 

Then there's the level that cannabis can disrupt other markets. Canopy Growth CEO Bruce Linton thinks cannabis could affect other markets that combined are worth $500 billion annually. He has suggested that cannabis products could capture significant share from the beverages, pharmaceuticals, and tobacco markets. 

Note that so far we've only addressed the market opportunity at a macro level. Another make-or-break variable is how effectively Canopy Growth can capitalize on the opportunities it has.

Canopy Growth's prospects

It seems a reasonable argument that the global marijuana market will increase dramatically in the future. It also seems reasonable to believe that Canopy Growth will be, as it is now, a major player in that market.

Different investors will disagree on exactly how good Canopy's prospects are, though. Let's examine the viewpoint of one investor -- Constellation Brands (NYSE:STZ). The big alcoholic-beverage company invested around $190 million in Canopy in 2017 and followed up with another $4 billion investment last year.

What kind of prospects did Constellation see for Canopy Growth? The distributor of Corona and Modelo beers estimated that the global cannabis market would top $230 billion within the next 15 years. Constellation projected that Canopy would be able to capture between 30% and 40% of the Canadian market and between 5% and 15% of the market in the U.S. and the rest of the world.

If we use the midpoints of Constellation's estimated market share ranges and its projections for the global cannabis market, Canopy Growth could be generating close to $26 billion in annual revenue in the future. That level should easily give the company a market cap of well above $100 billion.

The million-dollar question

But can Canopy Growth be a millionaire-maker stock? Not for most investors. The problem, though, is that a market cap of $100 billion or even $200 billion isn't enough.

Let's say you bought $10,000 worth of Canopy Growth stock. To make you a millionaire, that investment would have to grow a hundredfold. That means Canopy would have to increase its market cap from close to $17 billion today to around $1.7 trillion. Just FYI, there aren't any stocks on the market today that even crack the $1 trillion mark. 

Maybe someone who bought $200,000 or so of Canopy Growth shares could be able to turn that initial investment into $1 million or more over a long period. But if you have that much money to invest in one stock, you're probably already a millionaire.

So the answer to the million-dollar question for Canopy Growth is a resounding "no." However, if the company can come anywhere close to achieving the potential that Constellation thinks it can, the stock will make current investors a lot richer down the road. But if you're really looking to become a marijuana millionaire, you'll need to find another stock that has even more room to run than Canopy Growth does.

Keith Speights has no position in any of the stocks mentioned. The Motley Fool recommends Constellation Brands. The Motley Fool has a disclosure policy.