While investing in stocks is a terrific way to secure a comfortable retirement, your plans can go awry in plenty of ways. One of the worst is to find out (belatedly) that you have F-rated stocks that are holding you back.

F-rated stocks get the worst grades from the Portfolio Grader. That’s the free tool that evaluates every stock based on earnings performance, momentum, analyst sentiment and other factors.

The Portfolio Grader assigns an “A” through an “F” grade, and if you’ve got F-rated stocks, you’re probably not doing so well in your trades.

I like the Portfolio Grader’s ratings to give me a quick look at stocks that are underperforming or doing well. It’s a great sanity check for investors to run their holdings through the tool for a checkup. Or you can use the Portfolio Grader to help screen for new stocks expected to outperform and then dump the F-rated stocks.

Now that we’re in May, it’s time to make sure you don’t have any of these names – they’re among the F-rated stocks to avoid right now.

Tupperware (TUP)

Tupperware (NYSE:TUP) is an excellent example of what happens to a company that stubbornly refuses to grow.

The maker of plastic food containers has been a household name for years, but now there are serious questions about whether it will survive.

Sure, Tupperware was pretty revolutionary when it came out more than 70 years ago. People could store leftover food in an airtight container, helping to stretch the family food budget.

Just buying Tupperware was an event. The containers famously weren’t available in stores, and e-commerce wasn’t even a thought in the 1950s. If you wanted to buy some Tupperware, you had to go to a Tupperware party, a get-together in someone’s home.

But it’s not 1950 any longer. Plenty of plastic containers are on the market, coming in pretty much any conceivable size. You can get them in grocery stores, discount stores and online. Generic containers that are readily available quickly replaced tupperware.

Tupperware belatedly started selling its containers nationwide in Target (NYSE:TGT) stores late last year, but it’s too late. TUP stock is down to about $1 per share and has fallen more than 74% since the beginning of the year.

Tupperware’s plight exemplifies why businesses can’t just go stagnant. TUP stock has an “F” rating in the Portfolio Grader.

Exela Technologies (XELA)

Exela Technologies (NASDAQ:XELA) is in turmoil. The company has a market capitalization of $43 million and a debt of $1.1 billion. That’s not a ratio any investor should be happy with.

Overall, Exela does a lot. The company specializes in business automation and has more than 4,000 customers in 50 countries. The company had revenues of $1.08 billion last year.

But the revenue isn’t growing as you would expect. Exela’s revenue fell by nearly $90 million last year. Profits were also down by $77.9 million, coming in at $199.9 million.

Exela blames inflation, the rising dollar compared to other global currencies and a tight job market.

None of those situations will be over soon. Exela hopes to cut expenses this year by roughly $70 million. And it’s seeking shareholder approval for a reverse stock split of 1-for-100 or 1-for-200 to try to get its stock back up over a dollar.

A month ago, when I wrote about Exela, the stock was at a nickel per share. XELA stock has an “F” rating in the Portfolio Grader.

SNDL (SNDL)

SNDL (NASDAQ:SNDL), the Canadian cannabis and alcohol company previously known as Sundial Growers, was a popular meme stock a couple of years ago. Shares were around $20. Now they’re less than $2.

Cannabis stocks didn’t take off the way investors were banking on because the U.S. fumbled the ball on federal decriminalization.

There were widespread expectations that a Biden White House coupled with Democratic control of both houses of Congress after the 2020 election would lead to changes in federal law that would make recreational marijuana use legal.

But it never happened, as Washington was more focused on a faltering economy and Russia’s invasion of Ukraine. Now it appears legalization is on the back burner, and recreational marijuana will remain a state issue.

SNDL stock is down 22% this year and has an “F” rating in the Portfolio Grader.

Nikola (NKLA)

Nikola (NASDAQ:NKLA) is an electric vehicle company specializing in hydrogen-electric trucks and other heavy-duty vehicles. The Tre BEV truck has a range of 330 miles before needing a charge; the Tre FCEV hydrogen truck is expected to be available in the year’s second half.

But Wall Street remains impressed with the company. Shares are down more than 57% this year and 94% since June 2021. Earnings in the fourth quarter were a disaster, with Nikola reporting just $6.56 million in revenue when analysts expected $33.5 million. You never want to see a company miss estimates by 80%.

Nikola said it produced 133 trucks in the fourth quarter but delivered just 20 to dealerships.

And don’t forget; this is the same company that saw its founder convicted on wire and fraud charges last year for inflating Nikola’s stock price by making false claims about the trucks.

NKLA is a hard pass for me and gets an “F” rating in the Portfolio Grader.

Tilray Brands (TLRY)

Another Canadian cannabis company, Tilray Brands (NASDAQ:TLRY), makes this list of F-rated stocks to avoid.

Tilray, you may remember, traded at more than $140 once (back in 2018). Today you can pick up shares for about $2.50. In the last 12 months, the stock has been down by 52%.

Earnings for the company’s fiscal third quarter of 2023 raised some red flags. Revenues of $145.59 million fell 4% on a year-over-year basis. They were also lower than analysts’ expectations of $151.02 million.

The company had a net loss for the quarter of $1.19 billion, a year after posting a quarterly profit of $52.47 million.

The company’s cash and cash equivalents of $164.99 million were significantly lower than nine months ago when Tilray had more than $415 million.

Tilray is rolling out some new products, is getting into the brewery business, and has an acquisition lined up (more on that in the next segment), but it doesn’t appear enough to turn the tide for TLRY stock this month. TLRY gets an “F” rating in the Portfolio Grader.

Hexo Corp. (HEXO)

Yes, we’re back talking about Tilray again because Tilray last month announced its intentions to purchase competitor Hexo (NASDAQ:HEXO) for $56 million in a transaction expected to close this summer.

In the deal, Hexo shareholders will receive 0.4352 shares of Tilray stock for each share of Hexo they own. That implies a valuation of about $1.25 per share.

First, I’m not too excited about an F-rated stock buying another F-rated stock. Hexo historically has been unprofitable, and it carries a total debt of $141 million. So I’m not getting too worked up about this trade.

There’s nothing to be gained by buying Hexo now. And if you’re investing in the long term, a purchase of HEXO stock is a bet that Tilray will turn things around. And you already know where I stand on that one.

HEXO also has an “F” rating in the Portfolio Grader.

Intel (INTC)

Intel (NYSE:INTC) is a semiconductor company that’s seen better days. Once one of the biggest and best names in computing, Intel’s revenue is falling through the floor.

In the first quarter, revenues of $11.7 billion were down by 36% from a year ago. And the company posted a net loss of $2.8 billion, the biggest quarterly loss in the company’s history.

A year ago, Intel had a net profit of $8.1 billion and $1.98 per share.

But I wouldn’t count Intel out in the long term. Intel hopes to turn its factories into foundries to make chips for other companies and bid on high-profile work like other, more successful chip makers.

That’s a great goal. But it’s a long time down the road, with a target of 2026 before Intel thinks it will compete on that type of stage.

That doesn’t help investors in May, so for now, Intel is an F-rated stock in the Portfolio Grader.

On the date of publication, neither Louis Navellier nor the InvestorPlace Research Staff member primarily responsible for this article held (either directly or indirectly) any positions in the securities mentioned in this article.