Time and again, the stock market has demonstrated that it rewards patience. Despite the quickest drawdown of at least 30% in the broad-based S&P 500's storied history last year, investors who trusted in their investment theses have been handsomely rewarded. Over the trailing year, 910 stocks with a market cap of at least $300 million have doubled in value, with 62 of those stocks up by more than 500%.

While it's great to see the U.S. economy getting back on track, some of the most popular stocks investors are buying are downright awful businesses. Even with things looking up for the market as a whole, the following five ultra-popular stocks should be avoided like the plague in June.

A businessman holding up his hands, as if to say, no thanks.

Image source: Getty Images.

AMC Entertainment

There's absolutely no question that the No. 1 stock to avoid like the plague in June is movie theater chain AMC Entertainment (AMC 9.56%). It's far and away the most disassociated stock from its underlying business.

As most folks probably know by now, retail traders from Reddit, Twitter, and other social media platforms have banded together to buy shares and call options in AMC, which is a fairly heavily short-sold stock. Their goal being to effect a short squeeze -- i.e., an event where pessimists (short-sellers) feel trapped in their positions and run for the exit at once. Short squeezes are very short-term events and they have a very poor track record of success.

While I have a laundry list of issues with the basis for this trade, perhaps the single biggest is that retail traders are willingly ignoring AMC's dumpster fire of an income statement and balance sheet. This is a company that almost certainly won't be capable of paying back its debts when they come due by or before 2026. It's also now been hamstrung by the same retail investors who claimed to want to "save AMC." That's because AMC has maxed out how many shares it's authorized to issue, and can therefore not take advantage of higher prices with a capital raise. The May proxy vote would have allowed AMC to take advantage of this recent spike, but shortsightedness from retail traders killed that idea.

The AMC bull thesis is also built on a monument of misinformation. For example, retail traders believe hedge funds can bankrupt companies, when it's the operating performance and actions of businesses that determine whether or not they succeed or fail.

Suffice it to say, the willful ignorance of concrete data in AMC's income statements and balance sheets will come back to haunt these traders.

A close-up of a physical gold-colored Bitcoin stood on its side.

Image source: Getty Images.

Marathon Digital Holdings

June would also be a very good time to say goodbye to a number Bitcoin (BTC 0.82%) stocks. Cryptocurrency miner Marathon Digital Holdings (MARA 0.20%) may well top that list.

As I've been previously stated, I'm not a fan of Bitcoin. Although it's the largest digital currency in the world by market value, it's been stuck at handling a meager 300,000 transactions daily for more than a year and is accepted by approximately 15,200 businesses worldwide. That's nothing when you consider that there an estimated 582 million entrepreneurs around the globe. 

Bitcoin is also prone to long-winded downtrends. Over the past decade, the top cryptocurrency has lost at least 80% of its value on three separate occasions. That's bad news for Marathon for two key reasons. First, Marathon Digital mines Bitcoin, and is therefore reliant on higher prices to increase its revenue. It's not even clear if Marathon's mining operations would be sustainable if Bitcoin, once again, declines by more than 80% from its high of nearly $65,000.

The other issue is that Marathon purchased $150 million in Bitcoin earlier this year. While still up slightly on its investment, a protracted move lower in Bitcoin threatens to wipe out a good chunk of Marathon Digital's assets.

I've said it before and I'll say it again: Crypto mining stocks are the worst way to invest in Bitcoin.

A cannabis leaf set within the outline of the Canadian flags' maple leaf, with joints and a bud next to the flag.

Image source: Getty Images.

Sundial Growers

Following its late-May rally, Sundial Growers (SNDL -7.58%) has once more emerged as the top marijuana stock to avoid, as well as one of the worst stocks to buy, as a whole.

While marijuana is an intriguing place to put your money to work over the next five to 10 years, Canadian pot stock Sundial has consistently underperformed its peers and done nothing to build shareholder value.

In an effort to rid its balance sheet of debt, the company's management team began selling stock in October 2020... and it just hasn't stopped. Sundial has built up a cash hoard of 1.08 billion Canadian (about $894 million U.S.), but has done so by issuing more than 1.35 billion shares of stock in eight months. As of May 7, the company had 1.86 billion shares outstanding -- and this figure is likely to go higher with an $800 million at-the-market share offering approved earlier this year. Sundial is building up cash with no particular purpose in mind and drowning its shareholders in the process. 

With 1.86 billion shares outstanding, Sundial has virtually no chance of ever producing meaningful earnings per share, and it may not be able to get back above $1 per share on a consistent basis. It'll likely have to follow in the footsteps of serial diluter Aurora Cannabis and reverse split to get its share price to a respectable level.

As the icing on the cake, legal pot sales in Canada have grown significantly, while Sundial's marijuana sales have been slashed by a double-digit percentage. It's not where you want to put your money to work in the high-growth cannabis space.

A dry bulk vessel out at sea.

Image source: Getty Images.

Castor Maritime

As a general rule, penny stocks are penny stocks for a good reason. A company that consistently has a very low share price probably has an untested operating model, is losing money, and isn't creating value for its shareholders. This pretty much sums up Castor Maritime (CTRM -3.04%).

On paper, the operating model doesn't sound awful. Castor buys vessels capable of transporting dry bulk goods, such as grains, fertilizer, sugar, and steel. If the U.S. and global economy are rebounding from their pandemic lows, demand for dry bulk goods and daily charter rates should increase over time. Pretty straightforward, right?

The problem is that Castor Maritime didn't have the fleet or the finances to take advantage of this rebound. To compensate, it's been selling shares of its stock like it's going out of style to raise capital to buy new vessels. Castor ended 2020 with six ships but it now owns 26, when all are fully delivered. But it's the company's shareholders who paid the price for this shopping spree. Castor's share count has risen from 3.3 million shares on Dec. 31, 2019 to about 900 million (both figures are pre-split). 

However, last month the company had to enact a 1-for-10 reverse split to simply remain listed on the Nasdaq exchange. Issuing so many shares pushed Castor's share price below $0.40, and a $1 minimum share price is required for continued listing.

We've witnessed this same dilute and reverse-split story time and again in the shipping space. Castor is no different, which is why it should be avoided.

A father and son playing video games while seated next to each other on a couch.

Image source: Getty Images.

GameStop

Since we began with a Reddit pump-and-dump stock (AMC), it's only fitting that we end with another hype-driven Reddit stock: video game and accessories retailer GameStop (GME -0.68%).

Retail traders have flocked to GameStop for the exact same reason as AMC. GameStop had a larger percentage of its float held short than any other publicly traded company in January. This made it the ideal candidate for a short squeeze. Unfortunately, it's also spurred retail investors to now hone in on short interest data and absolutely nothing else about the companies they're buying.

To be clear, GameStop is a much, much better and more financially sound company than AMC. A recent share offering helped raise $551 million in gross proceeds, which means GameStop has wiped out its debt and has more than enough cash to move forward with its digital transformation. In fact, all of these avoidable stocks are likely OK on the liquidity front for the next three to five years... except AMC.

Where GameStop gets into trouble is if you dig into its operating performance. It's always been a brick-and-mortar-focused company. This worked well for two decades, but is problematic now that gaming has gone digital. Even with e-commerce sales up 191% last year, GameStop's total sales declined by more than 21%. In short, sales will be stagnant for years as the company shutters physical locations and invests in digital initiatives. Such challenges certainly don't merit a nearly 1,100% gain on a year-to-date basis.