Much like the cannabis industry at large, it’s been a swift half-decade of maturation for the nation’s largest marijuana trade show.

Customers line up to be some of the first people to legally purchase recreational marijuana at Reef Dispensaries in Las Vegas on Saturday, July 1, 2017. Chase Stevens Las Vegas Review-Journal @csstevensphoto

Budtender Tom Nieves displays marijuana products to customers during the first day of recreational sales at Acres Cannabis in Las Vegas on Saturday, July 1, 2017. Chase Stevens Las Vegas Review-Journal @csstevensphoto

Budtender Tom Nieves, right, assists customer Ethan, of Henderson, during the first day of recreational marijuana sales at Acres Cannabis in Las Vegas on Saturday, July 1, 2017. Chase Stevens Las Vegas Review-Journal @csstevensphoto

A customer looks through marijuana items as recreational sales become legal in Nevada at Reef Dispensaries in Las Vegas on Saturday, July 1, 2017. Chase Stevens Las Vegas Review-Journal @csstevensphoto

Customers line up to be some of the first people to legally purchase recreational marijuana from a dispensary at Reef Dispensaries in Las Vegas on Saturday, July 1, 2017. Chase Stevens Las Vegas Review-Journal @csstevensphoto

Much like the cannabis industry at large, it’s been a swift half-decade of maturation for the nation’s largest marijuana trade show.

About 400 people attended the initial iteration of the Marijuana Business Conference when it debuted in Denver in 2012. Back then, just 16 states had legal medical marijuana, and no states were selling recreational cannabis.

Now 29 states have legal medical weed. Eight states, including Nevada, have legalized the recreational product.

Reflecting that industry growth, the conference, which runs from Wednesday to Friday at the Las Vegas Convention Center, could see upwards of 17,000 pot professionals and investors this time around, said Chris Walsh, vice president of editorial and strategic development for Marijuana Business Daily, the Denver-based cannabis business news outlet that produces the conference.

“I don’t think any of us predicted this a few years ago,” Walsh said Monday.

The conference’s numbers might seem small when compared to the likes of CES and its 165,000-plus attendees, but MJBizCon touts itself as “by far the world’s largest gathering” of marijuana executives and vendors each year.

The conference started after the editors at Marijuana Business Daily saw a need to bring the industry executives together and maybe find some investors.

This year — the fourth consecutive year MJBizCon has been held in Las Vegas — will see the expo move from the Rio to the larger Las Vegas Convention Center to fit the thousands of new attendees, along with nearly 700 cannabis-related exhibits and more than 100 speakers.

But more than just the numbers have changed for MJBizCon.

Walsh said the biggest shift since those first few years has been the influx of “mainstream professionals,” people from banking, accounting and various technology fields who are now looking to invest in or even start their own cannabis-related business.

“It’s a reflection of how legitimate this industry is becoming,” Walsh said.

Contact Colton Lochhead at clochhead@reviewjournal.com or 702-383-4638. Follow @ColtonLochhead on Twitter.