Cannabis stocks saw a bright start to the week, with broad-based gains across North American markets.

The North American Marijuana Index, which tracks the top cannabis stocks in the US and Canada, was up 1.3% to 250.7 points by Monday's close. The Horizons Marijuana Life Sciences Index ETF was up 2.5% to C$19.41. The OTCQX Cannabis Index was down 1.7% at 771.4 points.

Buds

Tilray Inc (NASDAQ:TLRY) shares soared Monday, up 12.1% at US$43.51 in New York on news that it plans to acquire its largest stockholder.

The cannabis cultivation company signed a non-binding letter of intent with Privateer Holdings Inc, the equity fund created by PayPal Holdings Inc (NASDAQ:PYPL) founder Peter Thiel, to sell its 77% stake in the company over the next two years.

“We appreciate the long-term confidence that Privateer has in the Tilray business and we look forward to having their investors as part of our stockholder base," said Tilray's CFO Mark Castaneda. "We believe this transaction will give Tilray greater control and operating flexibility, while allowing us to effectively manage our public float.”

Other gainers Monday included Harvest One Cannabis Inc (CVE:HVT) (OTCMKTS:HRVOF), which was up 1.4% at C$0.73 and up 2.7% at US$0.56.

Last week, the firm announced that its wholly-owned subsidiary Satipharm Ltd will distribute its proprietary Satipharm CBD Gelpell capsule in the UK and Ireland.

Harvest One, based in Vancouver, British Columbia, will distribute the 10 miligram CBD capsule through Holland & Barrett, Europe's largest retailer of nutritional supplements and wellness products.

Also on the rise Monday was Cronos Group Inc (NASDAQ:CRON) (TSE:CRON), which was up 8.9% at US$17.36 in New York, up 9.1% at C$23.05. 

The firm didn't release any news, but last week earned a rare double upgrade from analysts at Bank of America Merrill Lynch. Analyst Christopher Carey upgraded the cannabis company to Buy from Underperform and boosted his price target to $20 from $13. 

Duds

On Monday, shares of US multi-state cannabis operator Cresco Labs Inc (OTCMKTS:CRLBF) (CSE:CL) were on the decline, down 6.1% at C$12.72 in Toronto, off 6% at US$9.60 in New York on no news. 

The firm is currently undergoing expansion, with eyes on Illinois, after the state recently approved cannabis for recreational adult use, set to go into law in 2020. 

Other laggards Monday included Green Growth Brands (CSE:GGB), down 2.4% at C$3.30. 

The firm recently said it is aiming to enter the Florida market, with its medical cannabis operations, with a US$55 million acquistion of Spring Oaks Greenhouses. Spring Oaks holds a medical marijuana dispensary license and operates as a medical marijuana treatment center.