This year was shaping up to be a miserable one for Clover Health (CLOV -4.70%). Note the use of the past tense in that statement, though. Thanks in large part to Reddit users piling on, Clover's shares have soared in recent weeks.

Don't think that the waters are safe to jump aboard the bandwagon for Clover Health yet, however. Here's why this hot Reddit stock just gave investors an ominous warning.

A person with a concerned expression with head down looking  at a laptop.

Image source: Getty Images.

Brutal honesty 

All publicly traded companies want investors to buy their shares. Buying tends to beget more buying, which pushes the stock price up. It's rare that any company warns investors not to buy its stock. But that's exactly what Clover Health did recently.

Companies that plan to issue additional shares file a prospectus with the U.S. Securities and Exchange Commission (SEC). This prospectus gives potential investors a lot of information about the business and lays out the key reasons why they might want to buy the new shares.

Clover Health filed such a prospectus earlier this year, outlining its intent to issue additional Class B shares. These shares don't have the same level of voting rights as its Class A shares. Last week, the company submitted an amendment to the SEC for this prospectus. And that amendment contained a brutally honest message for potential investors.

The company acknowledged that its recent gains could be due to a short squeeze. Because of the potential for an additional short squeeze and its aftermath, Clover Health gave an unusually stark warning to investors: "Under the circumstances, we caution you against investing in our Class B common stock, unless you are prepared to incur the risk of losing all or a substantial portion of your investment." It also noted, "Investors that purchase shares of our Class A common stock during a short squeeze may lose a significant portion of their investment."

No fear?

Clover Health explained clearly what could happen with both its Class A and Class B shares. The company stated that if another short squeeze happens, once short-sellers cover their positions or if investors otherwise think the short squeeze has run its course, its stock price could fall quickly.

You might think that such an ominous warning would scare off many investors. Nope. Instead, it produced an opposite effect. Last week, shares of Clover Health soared by a double-digit percentage immediately after the company's amended prospectus with the serious warning was submitted to the SEC. 

This reaction might seem counterintuitive. After all, Clover Health informed investors in no uncertain terms about the risks they face with buying the stock. So why did the shares of the company surge instead of sink? I think there are different reasons for different investors.

Some truly believe in Clover Health and are willing to hold onto the stock regardless of what happens over the short term. Others are fully aware that the gains generated by a short squeeze could evaporate quickly but think they'll be able to sell in time to still make a big profit. Unfortunately, there could also be some who are new to investing and didn't pay attention to or didn't understand Clover Health's cautionary message.

Business vs. stock

It's always wise to think of buying a stock as buying a part of a business. That's exactly what you're doing when you buy shares of Clover Health or any other company. When the underlying business is strong and has great prospects, you don't have to be concerned about short-term volatility with the share price.

However, there are times when share prices get way out of alignment with the prospects of the underlying business. Short squeezes can often make this happen. In these cases, it's especially important to be careful in buying a stock. Sure, you're still buying a part of a business -- but you can pay a lot more than the business is actually worth.

In my view, there are several reasons to like Clover Health's underlying business. The company has an intriguing technology that physicians use. It's expanding into the original Medicare market, a move that could boost sales tremendously. Clover Health has a visionary management team.

But buying a stock that's a short squeeze candidate is risky if you aren't ready, willing, and able to sell shares immediately once the short squeeze ends. When a company issues a warning like Clover Health just did, the smart thing to do is to listen and take that warning seriously.