What happened

A pair of marijuana stocks, Tilray (NASDAQ:TLRY) and OrganiGram Holdings (NASDAQ:OGI), both dropped notably in price on Friday (by 5.2% and 7%, respectively).

The culprit seems to be another weed title, Canopy Growth (NYSE:CGC), which earlier in the day published an awful quarterly earnings release.

Marijuana bud burning.

Image source: Getty Images.

So what

Canopy Growth is a leading company in the sector. Since basically every cannabis business in North America remains very dependent on this continent's market, they have all struggled with the numerous challenges of operating in their industry. Therefore, wherever a big marijuana company goes, the others broadly follow.

This affected Tilray and Organigram, even though neither had proprietary bad news to report on Friday. If either company were somehow exceptional or had shown a ray of promise recently, they might not have been blasted by the Canopy Growth wave.

They're not exceptional, however. OrganiGram's latest quarterly results showed worrying revenue erosion, in addition to a host of other concerns. Tilray is managing to grow revenue, but its losses are considerable. Plus, there's little indication that a recent big acquisition -- Manitoba Harvest -- will be much of a game changer.

Now what

Canopy Growth is trimming expectations, saying that it's enacting a strategic reset to more narrowly focus its business. That should drive investors away from the stock, and if they can't get interested in Canopy Growth, they won't be eager to buy shares of Tilray or OrganiGram, either.