What happened

Shares of Planet Fitness (NYSE:PLNT), Hertz Global Holdings (NYSE:HTZ), and Avis Budget Group (NASDAQ:CAR), three companies that would greatly benefit from a rebounding economy, were jumping over 10% Monday morning as a number of positive developments give investors hope.

So what

One of the major driving forces for Monday's early rally was Federal Reserve Chairman Jerome Powell's comments Sunday on 60 Minutes:

There's a lot more we can do. We've done what we can as we go. But I will say that we're not out of ammunition by a long shot.

Powell also noted that the Fed could unleash new lending programs and adjust the pace of its asset purchases. But all investors need to hear is that the government is willing to do whatever is necessary to get COVID-19 under control and fuel an economic recovery.

Another positive driving force Monday morning was news that Moderna's experimental COVID-19 vaccine produced antibodies that could "neutralize" the virus in patients. Moderna's vaccine, mRNA-1273, has so far been found to be generally safe in an early-stage study, and has the National Institutes of Health's help to fast-track its regulatory review. The company hopes to begin late-stage trials as soon as July.

Now what

The news that the Fed has more ammunition to offset COVID-19 impacts, and that Moderna is seeing promise in a vaccine, are huge developments for companies like Planet Fitness, Hertz, and Avis, which have been hit hard by social distancing and travel restrictions. In fact, Hertz is nearing bankruptcy and just appointed a new CEO, Paul Stone. And while Hertz, Avis, and the broader auto industry have been crippled as travel remains minimal, Planet Fitness has suffered from closing its locations and posted its first top-line decline in its publicly traded history. Consumers have understandably avoided public gyms in favor of substitute products such as Peloton Interactive, which recently posted blowout financial results and boasts record subscription numbers.

Empty gym with unused equipment.

Image source: Getty Images.

Investors are clearly tuned in to what the Fed is doing to aid an economic recovery, as well as promising developments for vaccines that could help control COVID-19. These three companies desperately need the economy to return to a more normal state as soon as safely possible. Investors have an opportunity to buy out-of-favor stocks such as Hertz, Avis, and Planet Fitness. But they also need to do their due diligence and research companies' balance sheets and liquidity before blindly buying stocks that appear to be trading at a discount. Markets will eventually rebound, but not all companies will survive this COVID-19 related downturn.