The U.S.-listed shares of Canopy Growth Corp. /zigman2/quotes/200603886/composite CGC -1.06% /zigman2/quotes/202205609/delayed CA:WEED -0.92% dropped 4.2% in premarket trading Monday, after Stifel Nicolaus analyst Andrew Carter swung to bearish from bullish in the wake of the Canada-based cannabis company's disappointing earnings report and "significant" challenges ahead. The stock had plunged 20.0% on Friday after the fiscal fourth-quarter report. Carter cut his rating to sell after being at buy for at least the past year, and cut his price target by 22% to C$18. "Canopy Growth sports the resources to deliver on its ambitions of leading growth in the global cannabis category, but the resources have yet to produce tangible evidence of on an enduring right to win in the developing category," Carter wrote in a note to clients. "We believe course correction will be difficult, expenses will remain elevated, and catalysts for driving enthusiasm will be slow to develop necessitating a further re-rating for the shares." The stock has dropped 7.5% over the past three months through Friday, while the Cannabis ETF /zigman2/quotes/213173823/composite THCX -0.86% has gained 6.4% and the S&P 500 /zigman2/quotes/210599714/realtime SPX +1.01% has tacked on 3.1%.