A quick look at the long-term chart of the benchmark S&P 500 will demonstrate to any investor that optimism is rewarded over the long run. However, just because the broader market indexes head higher over time, it doesn't mean all stocks will be winners -- and Wall Street knows it.

Although a vast majority of Wall Street ratings and price targets on publicly traded companies portend upside, some analysts see nothing short of calamity in the months and years that lie ahead for some of the most popular stocks. Based on the lowest Wall Street price target, the following three ultra-popular stocks could tumble between 81% and 98%.

A one hundred dollar bill on fire atop a lit stove burner.

Image source: Getty Images.

Moderna: Implied downside of 81%

Biotech stock Moderna (NASDAQ:MRNA) has been one of the fastest-growing and most successful investments since the beginning of 2020. However, Leerink Partners analyst Mani Foroohar sees things differently. Foroohar and Leerink have stuck by their sell rating and $85 price target on the company as it's soared. If Moderna were to fall back to $85, it would shed 81% of its value. 

On one hand, Moderna has been practically unstoppable, thanks to the successful development of mRNA-1273, one of the coronavirus disease 2019 (COVID-19) vaccines to receive emergency-use authorization in the United States. In late-stage clinical studies released last November, Moderna's two-dose regimen of mRNA-1273 led to a vaccine efficacy (VE) of 94.1%. Even though recent studies have shown that VE wanes over time, the initial VE offered by mRNA-1273 has made it one of the two most-popular inoculation options in developed markets.

Also working in Moderna's favor is the possibility that COVID-19 vaccines could become a recurring/seasonal thing. Mutations and variations of COVID-19 make it increasingly likely that it'll become an endemic disease. Without the ability to rid COVID-19 from the U.S. and other countries, booster shots may be necessary to combat it. In other words, Moderna's one-hit wonder could become a regular revenue stream.

On the other hand, mRNA-1273 is Moderna's only revenue-producing asset, and competition in the vaccine space is only destined to become more crowded. Even if Moderna's vaccine remains toward the top end in terms of efficacy, the sheer volume of doses that need to be administered globally will open the door to other successful drugmakers.

While Leerink's price target is potentially too aggressive to the downside, Moderna does have a lot to prove with a $181 billion market cap and only one marketed drug.

Former CEO Steve Burns standing next to a prototype of the Endurance pickup.

Now-former CEO Steve Burns standing next to a prototype of the Endurance all-electric. pickup. Image source: Lordstown Motors.

Lordstown Motors: Implied downside of 84%

Over the next decade, electric vehicles (EVs) could be one of the fastest-growing industries in North America. But Wall Street isn't too keen on one EV manufacturer, in particular: Lordstown Motors (NASDAQ:RIDE).

According to analyst Joseph Spak at RBC Capital, Lordstown is worthy of an underperform rating and a $1 price target. If this price target becomes a reality, Lordstown's shares will have fallen 84%.

Whereas there was both a clear bull and bear argument to share about Moderna above, the same can't be said of Lordstown Motors. It's been nothing short of a disaster.

In March, a number of allegations were levied against the company by short-side firm Hindenburg Research. Although a number of these allegations proved to be without merit, a committee formed by Lordstown's independent directors found that the company had exaggerated the number of pre-orders of its Endurance EV pickup. Both Lordstown's CEO Steve Burns and CFO Julio Rodriguez resigned in the wake of these findings.

To make matters worse, Lordstown Motors may not have enough capital to survive the next year. It costs a pretty penny to build a new automaker from the ground up. Even though the company ended June with $366 million in cash, it reported a second-quarter loss of $108 million. 

The real issue, as my auto-focused colleague John Rosevear notes, is that the company's Endurance pickup isn't anywhere close to being on schedule. Lordstown will probably see Endurance deliveries to customers commence in the second quarter of 2022, which doesn't exactly align with the idea put forward by the company that production would begin in September.

With few avenues to raise cash and lukewarm demand for Endurance, a $1 price target may even prove too generous.

Two movie theater admission tickets placed in a full tub of popcorn.

Image source: Getty Images.

AMC Entertainment: Implied downside of 98%

And then there was meme stock kingpin AMC Entertainment (NYSE:AMC). AMC shouldn't be a surprise on this list, as the most bullish investment bank on Wall Street sees the company losing nearly 70% of its value, as of this past weekend. On the other end of the spectrum, Alan Gould at Loop Capital foresees AMC eventually heading back to $1 a share. That would be a decline of 98%, for those of you keeping score at home.

The reason AMC has shot out of a cannon and pushed well beyond Wall Street's collective price targets is the unwavering support of retail investors who believe it'll undergo another short squeeze. This is a very short-term event whereby pessimists who are betting against a stock (i.e., short-sellers) run for the exit at the same time. Since short-sellers have to buy shares to cover their short positions, it can cause a rising stock price to briefly go parabolic.

But as Gould and other analysts have noted with AMC, the numbers don't add up. While it's impossible to pinpoint when emotion will stop being the driving force behind AMC, the operating performance of a company and its balance sheet always dictate the long-term price performance of a company's stock. In this respect, the movie-theater industry has been in a nearly two-decade decline, with streaming services siphoning off moviegoers and AMC building up share in an industry where the proverbial pie is getting smaller.

The far greater concern for AMC is the amount of leverage it took on to survive the pandemic. Although the company ended June with $2.023 billion in liquidity ($1.81 billion of which is cash), it's also sitting on nearly $5.5 billion in corporate debt, $420 million in deferred rent, and close to $4.9 billion in lease liabilities.

By the end of 2023, the company expects to lay out $2.51 billion, at minimum, for lease liabilities and will likely have to repay its $420 million in back rent. That's $2.9 billion in upcoming payments over a 30-month period for a company that's still burning cash and has only $2 billion in liquidity.

To boot, AMC's retail investors won't approve any additional share offerings, leaving the company with no avenues to further raise capital. As with Lordstown, even a $1 price target might be generous when given enough time.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.