Looking to buy some discounted stocks heading into 2024? There are some good deals in the markets, but there are also some potentially dangerous and risky stocks you may want to steer clear of now. Three stocks investors should tread very carefully with include Altria Group (MO -0.37%), Plug Power (PLUG 1.26%), and Canopy Growth (CGC 2.41%). Here's why you may want to think twice before adding these stocks to your portfolio.

1. Altria Group

Tobacco giant Altria faces an uncertain future. Cigarette smoking is on the decline and the company is trying to transition to less harmful products, but that's easier said than done. Over the past nine months, the company has generated $18.5 billion in revenue, and of that, $16.5 billion has come from its smokable products. That's nearly 90% of its business.

Its bread and butter is based on an industry that's in decline. The company says that the volume of domestic cigarette shipments has dropped 10.5% year to date. While its revenue won't go to zero tomorrow, this is a big problem that Altria needs to sort out before being a tenable long-term investment.

Although the stock looks cheap -- it trades at less than 9 times earnings -- there's good reason for the discount given the underlying business faces many question marks. And its high-yielding dividend of 9.4% may look attractive, but it also comes with a lot of uncertainty because if Altria struggles to grow, a dividend cut may be a possibility in the near future.

2. Plug Power

An even riskier stock than Altria is Plug Power. The green hydrogen company raised "going concern" issues recently, which means that it's not confident about its own ability to survive. There aren't much more serious red flags than that for investors. It's trading at just 0.8 times its book value and its shares are down 64% this year, and so some investors may feel compelled to take a contrarian position on the stock.

But the risk is simply too high. The biggest problem with the business isn't even that it has posted a $726 million loss over the past three quarters. More alarming is the $864 million in cash it has burned through during that time frame. It can't afford to keep up that pace because the company only had $111 million in cash and cash equivalents as of the end of September; the risk for share dilution is high.

There's not a whole lot of power left in Plug Power's stock. And while it has plunged this year, investors shouldn't expect a big turnaround in 2024. Investing in green energy can be a good move, but not if a company doesn't have strong enough financials to support its long-term growth.

3. Canopy Growth

Another company that has raised going concern risks is Canadian cannabis producer Canopy Growth. The days of this being a promising growth stock are long gone. Instead, the company boasts of moving toward becoming an "asset-light" business as it looks to feverishly cut whatever expenses it can for the sake of keeping its operations afloat.

But that isn't an easy task. It recently got rid of sports nutrition company BioSteel, which was its fastest-growing business unit. And on Monday, it also announced the sale of its skincare and wellness brand, This Works. Whether that's enough to stop the cash burn, however, is uncertain. And at the very least, disposing of assets will only ensure its top line continues to decline.

Canopy Growth's net revenue totaled just under 70 million Canadian dollars for the period ended Sept. 30 and was down 21% year over year. On top of this, the company also burned through more than CA$66 million cash from its day-to-day operating activities. Its cash and short-term investments totaled CA$270 million as of the end of September, so the business does have some breathing room, but it's still in a tough situation.

With the stock down 79%, investors are likely better off resisting the temptation to take a chance on this highly risky investment.