What happened It's Monday, and marijuana stocks are vaporizing. In 11:30 a.m. EDT trading, Canopy Growth (NASDAQ: CGC) stock is down a depressing 4.4%, and cannabis rivals Aurora Cannabis (NYSE: ACB) and Hexo (NYSE: HEXO) have both tumbled about 8% each. And if you want to know why, ask Aphria (NASDAQ: APHA). Image source: Getty Images. So what Yes, unfair as it may feel, the stock to blame for Canopy's, Aurora's, and Hexo's declines today is none of the above, but rather their cannabis-growing rival Aphria, which reported its fiscal Q3 2021 earnings results this morning. Suffice it to say that the news was not good. Sales at the Canadian cannabis company grew a respectable 6% to CA$153.6 million in Q3 2021, but that was well below the CA$166.2 million that analysts had predicted. Worse, Aphria reported a CA$1.14-per-share loss for the quarter, versus the tiny profit (calculated according to generally accepted accounting principles or GAAP) reported a year ago. In terms of U.S. dollars, Aphria lost $0.91 per share. Now what Aphria blamed "the duration and impact of lockdowns across many of the regions we operate in, particularly in Canada" for its disappointing results, but insisted that it "remains well-positioned with our leading brands and market share to experience a robust increase in our top-line as the market improves" and said it is still "excited about the strategic opportunities for incremental growth," particularly in the U.S. market. Regardless, the fact that Aphria's gross profits on its sales declined by nearly half in the quarter suggests that demand for the product isn't necessarily Aphria's (or Canopy's or Aurora's or Hexo's) biggest problem going forward. Shrinking profit on growing sales speaks to declining pricing power in the industry as oversupply continues to weigh on profitability for medical marijuana and recreational marijuana alike. That's not good news for Aphria's future. It's not good news for Canopy Growth, Aurora Cannabis, or Hexo, either. 10 stocks we like better than Canopy Growth Corp.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 Canopy Growth Corp. 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 Rich Smith has no position in any of the stocks mentioned. The Motley Fool recommends HEXO Corp.. The Motley Fool has a disclosure policy.Source