Canadian cannabis company Tilray Inc.'s stock TLRY, +1.06% surged another 6% on Thursday, extending its prior-day gains on continued excitement ahead of Canada's full legalization of the substance on Oct. 17. Tilray had a rollercoaster day on Wednesday as the whole sector rallied, with trading halted five times for volatility. The stock is more susceptible than others to massive price swings as it has a small number of shares outstanding, is seeing strong short interest and few investors can loan the stock to short sellers, as MarketWatch's Max Cherney reported. Stifel analysts said Thursday they expect the Canadian addressable market to be worth about CAD$10 billion ($7.8 billion). "Clearly, valuations require global opportunities to be realized, though we question the pace of development and degree of advantage for these companies," they wrote in a note. Still, headlines around the world show other countries are taking a "more constructive stance" on cannabis, naming the U.K., Germany and South Africa as examples. The global market could be worth upward of $200 billion, which makes current valuations "more palatable." Tilray shares have gained almost 500% in one month. The S&P 500 SPX, +0.29% has gained 2% in the same time frame.