What happened Shares of Inovio Pharmaceuticals (NASDAQ: INO) declined on Tuesday after investment bank Roth Capital Partners released a bearish report on the biotechnology company. As of 12:45 p.m. EST, Inovio's stock was down 8.5%. So what Roth Capital analyst Jonathan Aschoff slashed his rating on Inovio from neutral to sell. He sees its share price falling more than 30% to $8 amid intensifying competition from the likes of Pfizer (NYSE: PFE) and Moderna (NASDAQ: MRNA). Inovio shareholders could suffer steep losses, according to a Roth Capital analyst. Image source: Getty Images. In the past week, Pfizer and Moderna have both said their separate coronavirus vaccine candidates could be more than 90% effective at preventing COVID-19. Given these results -- and the fact that their phase 3 studies have progressed to the advanced stages -- both Pfizer and Moderna could soon request emergency use authorization from the U.S. Food and Drug Administration. Now what Inovio, meanwhile, is just beginning its Phase 2 study for its experimental COVID-19 vaccine. And with Pfizer and Moderna's clinical trial data setting the bar extremely high, it won't be easy for Inovio's vaccine candidate to compete effectively with these two healthcare giants. With Inovio's share price up a staggering 289% in 2020 up until today, investors are understandably taking some profits off the table. And should Moderna's and Pfizer's drugs prove to be safe and continue to demonstrate such high efficacy at combating COVID-19, Inovio's stock could continue to sell off in the days and weeks ahead. 10 stocks we like better than Inovio PharmaceuticalsWhen 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 Inovio Pharmaceuticals 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 Joe Tenebruso 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