What happened Thursday was a day to forget for most stock market investors, particularly holders of marijuana titles. Industry bellwethers Canopy Growth (NASDAQ: CGC), Aurora Cannabis (NYSE: ACB), Aphria (NASDAQ: APHA), HEXO (NYSE: HEXO), and Organigram Holdings (NASDAQ: OGI) all fell harder than the S&P 500 index at declines ranging from 6.1% (Aurora) to just over 8% (Aphria). So what The outlook for the marijuana industry has brightened significantly of late thanks largely to both a new presidential administration and a Senate leadership that are more amenable to federal marijuana reform. Image source: Getty Images. However, this has obscured the fact that cannabis companies remain speculative investments. Weed has only been legalized/decriminalized on a piecemeal, state-by-state basis, and weed companies face many other challenges, including lack of access to basic financial services, price-dampening black market competition, etc. Even the most successful operators struggle to turn a profit and limit cash burn. So, because they are speculative stocks, they tend to be on the firing line during market downturns. At such times, investors typically embrace better established, and/or more reliable cash and profit generators, and are more tempted to sell their perceived "long-shot" holdings. Now what This shouldn't dissuade investors of marijuana stocks which, despite those challenges, have a promising future. Among other positive developments, Aphria's coming merger with Tilray will make a powerful company, and HEXO is bulking up with the looming acquisition of Zenabis Global. Thursday's declines could very well present good "buy-on-weakness" openings for cannabis bulls. 10 stocks we like better than Aphria Inc.When investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now… and Aphria Inc. wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of February 24, 2021 Eric Volkman has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends OrganiGram Holdings. The Motley Fool recommends HEXO. The Motley Fool has a disclosure policy.Source