You could play it safe. Put your money in assets that aren't likely to lose their value. Maybe you might opt to buy shares of utility companies that enjoy monopolies. 

But not every investor wants to take the safe path that leads to smaller returns over the long run. Even normally risk-averse investors might want to take a walk on the wild side every now and then by buying stocks that hold the potential to deliver mouth-watering gains in a short period of time.

If you're one of those kinds of investors, consider stocks of biotechs with promising COVID-19 programs. If their pipeline candidates are successful, these companies could generate a lot of money relatively quickly. Here are three coronavirus stocks that I think could especially make you a fast fortune.

Hand holding briefcase with $100 bills sticking out

Image source: Getty Images.

1. Moderna

Everybody's talking about Moderna (NASDAQ:MRNA). And for good reason. The biotech ranks as a leader in the race to develop a COVID-19 vaccine. Some might even view Moderna as the leader in the race.

The New England Journal of Medicine published data from a phase 1 study of Moderna's COVID-19 vaccine candidate mRNA-1273 last week. The results generated a lot of excitement. Every participant in the study who received mRNA-1273 had neutralizing antibodies (which can prevent infection by the novel coronavirus). Even more encouraging, the study participants' levels of those neutralizing antibodies were higher than levels found in patients who recovered from COVID-19.

Moderna plans to kick off a phase 3 study of mRNA-1273 on July 27. If all goes well, the company could be on a fast path to winning FDA Emergency Use Authorization and full approval. Jefferies analyst Michael Yee thinks that Moderna's COVID=19 vaccine could make over $5 billion per year if it wins approval. 

Depending on what happens with other COVID-19 vaccine candidates in development, I suspect Yee's estimate could be too conservative. Also, if mRNA-1273 proves to be both safe and effective, it should greatly increase investors' appreciation of the rest of Moderna's pipeline. Even though the biotech stock has soared so far this year, it should go a lot higher if the company's COVID-19 vaccine candidate achieves its potential.

2. Novavax

Novavax (NASDAQ:NVAX) isn't as far along in clinical development with its COVID-19 vaccine candidate as Moderna is. However, it's not too far behind: The biotech expects to report preliminary results from the phase 1 part of its phase 1/2 study of NVX-CoV2373 later this month. If all goes well, Novavax will advance the vaccine candidate to phase 2 testing. 

There has already been a lot of money bet on Novavax's success. The Coalition for Epidemic Preparedness Innovations (CEPI) awarded up to $388 million for the development and production of NVX-CoV2373. The U.S. Department of Defense gave Novavax a contract worth up to $60 million to manufacture the vaccine for the military. Operation Warp Speed, the federal government's program to accelerate the development of COVID-19 vaccines, announced $1.6 billion in funding for NVX-CoV2373.

While Novavax's COVID-19 vaccine program has been in the limelight, the company has another pipeline candidate that could also be a big winner in the near future. Novavax announced positive late-stage results for flu vaccine candidate NanoFlu in March. Its next step is to file for FDA approval. If approved, NanoFlu could become a blockbuster.

3. Vaxart

Now for the most speculative of the group. Vaxart (NASDAQ:VXRT) hasn't even advanced its COVID-19 vaccine candidate to clinical testing yet. But its shares have skyrocketed close to 4,000% so far this year. I think it's possible that this could be just the beginning of a fantastic run for Vaxart.

Most COVID-19 vaccine candidates in development rely on injections. For that matter, most vaccines of any type are injected. Vaxart, however, focuses on oral vaccines. Not only would these vaccines be easier to swallow (pun fully intended) for many people who don't like needles, they also can be stored at room temperature. Those are two huge advantages.

It's not surprising that Vaxart's oral COVID-19 vaccine candidate was selected to be part of a preclinical study in non-human primates that Operation Warp Speed is funding. Vaxart hopes to advance its candidate to a phase 1 clinical study later this year. If the company achieves success with its oral COVID-19 vaccine, that should open opportunities for its other oral vaccine candidates. Vaxart just might be the biggest winner of the three over the long run.

The operative word

Moderna, Novavax, and Vaxart could absolutely make you a fast fortune over the next few years. The operative word in that statement, though, is could

All three of these biotechs still face significant risks. That's especially true for Vaxart, which is well behind both Moderna and Novavax in terms of pipeline progress. You could potentially incur big losses with these stocks as quickly as you could make big gains (and perhaps even more quickly).

Risk is the trade-off you have to make to have an opportunity to achieve huge returns. Only aggressive investors should entertain the possibility of buying Moderna, Novavax, or Vaxart. If you want to play it safe (or at least safer), you'll need to look at other stocks.