In retrospect, buying Curaleaf Holdings (OTC:CURLF) at the beginning of 2020 was an easy decision. The multistate cannabis operator was well positioned in 12 states, including the fast-growing medical cannabis market in Florida. Curaleaf was gearing up to acquire Grassroots, a move that would make the company an even bigger player in the U.S. cannabis industry.

Sure enough, the marijuana stock went on to skyrocket 90% last year. It's up nearly 20% so far in 2021. But past performance doesn't always translate into great future results. Should you buy Curaleaf stock right now? Here are three good reasons to seriously consider doing so. 

Cannabis leaves on top of $100 bills.

Image source: Getty Images.

1. Major new markets await

In Curaleaf's third-quarter results press release, then-CEO Joseph Lusardi (who's now executive vice chairman) pointed out that the company "remains incredibly well-positioned following the transformative legalization of adult-use cannabis in Arizona and New Jersey." Lusardi was exactly right. 

Arizona and New Jersey residents voted in November to legalize recreational pot. Both states already had sizable medical cannabis markets. Pot will be really big business going forward, though. Legal cannabis markets in both Arizona and New Jersey are likely to quickly top $1 billion. 

Curaleaf is in good shape to expand in each of these states. The company already ranks No. 1 in New Jersey's medical cannabis market with a market share of around 35%. It's No. 2 in Arizona's retail medical cannabis market. You can expect that Curaleaf will leverage its existing operations to become one of the leaders in both states' recreational pot markets. 

2. Other big markets could be on the way

Don't think for a second that there isn't peer pressure on neighboring states when one state legalizes marijuana. Legislators are always looking for ways to generate more revenue to fund programs. It's not surprising at all that Lusardi specifically mentioned "the potential of future adult-use in New YorkPennsylvania, and Connecticut" in his Q3 remarks.

New York Gov. Andrew Cuomo has already announced his proposal to legalize recreational marijuana in the Empire State. He thinks the effort could net the state over $300 million per year in additional tax revenue. Grand View Research projects that New York's total cannabis market will be worth around $7 billion annually by 2025. 

Again, Curaleaf is in a prime position to profit if New York, Pennsylvania, and/or Connecticut legalize recreational marijuana. The company ranks first in each of these states' medical cannabis markets. In New York, Curaleaf has a strong market share of at least 25%. 

3. A possible exchange 

Thanks to wins in Georgia's special Senate runoffs last week, Democrats will control both U.S. legislative chambers as well as the White House in 2021. That makes the likelihood that marijuana could be decriminalized at the federal level greater than it's ever been.

Federal decriminalization isn't the same thing as marijuana legalization across the U.S. However, it would mean that the companies that produce and sell cannabis wouldn't be in violation of federal laws. That would clear the way for Curaleaf to list its shares on a major U.S. stock exchange.

Currently, U.S. investors can only buy the stock over the counter (OTC). Some brokerages, including the popular Robinhood platform, don't allow trading of many OTC stocks such as Curaleaf. If Curaleaf is able to list its shares on a major U.S. stock exchange such as the Nasdaq or New York Stock Exchange, look for a big bump for its share price. 

Why not buy Curaleaf?

Are there reasons not to buy Curaleaf? I can think of two off the top of my head.

First, many investors avoid "sin" stocks. Curaleaf would be out of the question for these investors because of its involvement in the recreational pot business.

Second, there are arguably better stocks to buy right now -- even marijuana stocks that could potentially soar higher than Curaleaf will. The company's market cap of $9 billion makes it bigger than several of its U.S. peers. Some of these smaller stocks could deliver greater gains because of the same three reasons given for buying Curaleaf. Several of those stocks outperformed Curaleaf in 2020 and could do it again this year.