Go big or go home: That's the attitude that many Robinhood investors seem to have. The list of the 100 most popular stocks on the trading platform includes quite a few stocks that could be huge winners -- or huge losers. This kind of high-risk/high-reward proposition won't appeal to every investor. But if you have a really aggressive approach to investing, here are three ultra-risky Robinhood stocks that just might make you a fortune. Image source: Getty Images. iBio In August, iBio (NYSEMKT: IBIO) announced encouraging preclinical results for experimental COVID-19 vaccine IBIO-201. Those results showed that IBIO-201 generated a robust immune response in mice. iBio has also tested another experimental COVID-19 vaccine, IBIO-200, in preclinical trials. However, in September the biotech selected IBIO-201 as its candidate to advance into toxicology studies. If all goes well with those studies, the company hopes to move forward with clinical-stage testing of the vaccine in humans. In addition, iBio licensed a COVID-19 therapeutic candidate, ACE2-Fc, from Planet Biotechnology. The biotech's only clinical-stage pipeline candidate right now is IBIO-400, an experimental swine fever vaccine for animals. It's still very early for all of iBio's programs. If the company's COVID-19 vaccine and/or its therapeutic candidate go on to deliver great results in clinical testing, though, the biotech stock could soar a lot higher than its year-to-date gain of more than 580%. Inovio Pharmaceuticals Inovio Pharmaceuticals (NASDAQ: INO) could be a lot closer to success with its coronavirus vaccine candidate, INO-4800. The company had hoped to begin a phase 2/3 clinical study of the experimental vaccine in September. However, the Food and Drug Administration placed the study on partial clinical hold because it had questions about the trial. It's now a waiting game for Inovio. The biotech responded to the FDA's questions and could find out within the next few weeks if it can move forward with the planned phase 2/3 study of INO-4800. A positive decision by the FDA would almost certainly send Inovio's shares into orbit. Inovio's pipeline has plenty of other potential winners. VGX-3100 stands at the top of the list. The company is evaluating the experimental drug in a late-stage study targeting precancerous cervical dysplasia caused by human papillomavirus (HPV). Inovio expects to report results from this study in the first half of 2021. The biotech also is evaluating VGX-3100 in phase 2 studies for potentially treating HPV-related anal and vulvar dysplasia. Its pipeline also includes 10 other programs. Sorrento Therapeutics You'll be hard-pressed to find a company with more irons in the COVID-19 fire than Sorrento Therapeutics (NASDAQ: SRNE). The biotech is working on tests, treatments, and vaccines targeting the coronavirus. Sorrento's lead pipeline candidate, abivertinib, is currently in phase 2 testing for potential treatment of severe cases of COVID-19. The immunotherapy also being evaluated in a pivotal late-stage study targeting non-small cell lung cancer. The biotech hopes to win FDA emergency use authorization for a COVID-19 antibody test and diagnostics test. It's advanced one experimental antibody therapy targeting COVID-19 into an early stage study and has filed for FDA approval to advance two other antibody therapies into clinical testing. Sorrento also has a coronavirus vaccine candidate, STI-3333. In addition to its COVID-19 programs, Sorrento's pipeline includes several clincal-stage candidates targeting cancer and pain. Although its shares have nearly doubled so far this year, success with any of its clinical programs would likely provide a big catalyst for Sorrento. Putting the ultra in ultra-risky Any or all of these three popular Robinhood stocks could easily generate tremendous returns, perhaps even before the end of 2020. However, iBio, Inovio, and Sorrento are ultra-risky for a reason: Their prospects hinge on clinical results that might not turn out well. The biotech stocks might make investors a fortune, but they could just as easily be disastrous. The possibility of going big comes joined at the hip with the potential to go home with empty pockets. 10 stocks we like better than Sorrento TherapeuticsWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Sorrento Therapeutics wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of October 20, 2020 Keith Speights has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source