People flock to public celebrations across the country that, in some cases, attract crowds of thousands. Pot-related businesses also show off their products.

Over the weekend in Colorado, hordes of people got a head-start in what is a regulated market for both medical and recreational marijuana. In Denver, roughly 125,000 fans of Colorado’s progressive marijuana laws gathered on public property for an annual 4/20 rally — the number has a murky history, but it’s a nod to the time of day when stoners often light up — while thousands more in that city attended High Times‘ annual Cannabis Cup.

(For more on the Cannabis Cup and the 4/20 holiday, read this excerpt from author Bruce Barcott’s new book, Weed the People: The Future of Legal Marijuana in America.)

At both events, vendors pitching products — from cannabis strains and marijuana edibles to vaporizers — as they look to cash in on the so-called “green rush” in a regulated pot industry that could generate more than $10 billion in annual legal sales by 2018, according to The ArcView Group, a cannabis-focused investment firm. Twenty-three states have legalized medical marijuana, while four states and Washington, D.C. have legal recreational pot.

The marijuana industry still faces legal and political obstacles, including federal tax issues and a lack of available banking options, but the industry still manages to grow. Indeed, ArcView estimates the industry’s sales increased 74% last year, to $2.7 billion.

In honor of Monday’s marijuana holiday, here are five of cannabis companies with most reason to celebrate.

1 Privateer Holdings

The marijuana investment company recently closed a $75 million fundraising round that included the Founders Fund, an investment firm created by PayPal cofounder Peter Thiel, taking a multi-million dollar stake. The investment was a big one for both Privateer and the cannabis industry on the whole because it represented the first major institutional funding in a marijuana company.

Privateer, which says the $75 million funding is the largest yet in the pot industry, operates a trifecta of pot-related companies: Canadian medical marijuana growing facility Tilray; a Yelp-like website to search marijuana dispensaries called Leafly; and, the recently unveiled Marley Natural, which will sell recreational cannabis strains branded with the name of legendary reggae musician Bob Marley.

2 GW Pharmaceuticals

This British pharmaceutical company has been developing drugs derived from cannabis compounds THC and the non-psychoactive cannabidiol (which, unlike THC, does not produce a "high") for more than a decade. GW Pharmaceuticals (GWPH) is currently testing a new cannabidiol-based drug, called Epidiolex, that is intended to treat severe epilepsy in children and young adults. At the same time, investors who are eager to pump money into the cannabis industry's expanding medical research segment are sending up the company's shares.

GW's stock topped $100 per share last month and are up nearly 68% so far this year, giving the company a market value of about $2.2 billion.

3 Eaze

This medical marijuana delivery app has been billed as the "Uber for pot." And, while Eaze is nowhere close to the ride-hailing app's multi-billion dollar valuation, the delivery service that can bring pot to your door (assuming you live in a state where medical marijuana is legal) recently took in some major investment money. Eaze announced its $10 million Series A funding earlier this month from a handful of venture capital firms.

Interestingly, one of the reported investors in Eaze's funding round was Casa Verde Capital, a VC firm backed by rapper Snoop Dogg, a well-known pot-enthusiast who already has his own branded vaporizer.

4 MassRoots

This pot-focused social networking app overcame a brief exile from Apple's App Store earlier this year and has since grown to more than 275,000 users. MassRoots, which lets cannabis lovers connect and share pictures with one another, is now being traded as a penny stock after raising more than $1.3 million in funding through a pair of investment rounds that left the company valued at $25 million overall.

MassRoots' troubles with Apple seem to be over now that the app has added a geo-restricting function that limits its users to the 23 states with legal medical marijuana. CEO Isaac Dietrich told Fortune in February that his company is lining up advertisers in the hopes of capitalizing on its user base. Dietrich thinks MassRoots could see $1 million in monthly revenue within two years.

5 MedMen

MedMen managing partner Adam Bierman told Fortune last year that he wants his company to become "the Four Seasons of pot," referring to the luxury hotel chain. In other words, he sees the marijuana management and consulting firm becoming a trusted name in the industry that can manage medical marijuana businesses across the country. Currently, the focus is in Nevada, where MedMen is in talks to manage licensed dispensaries and cultivation facilities. As the company moves toward its goal of managing a bigger variety of pot businesses, MedMen will tap into the $3.75 million in funding it raised from investors last fall.

We’ve included affiliate links in this article. Click here to learn what those are.