(Bloomberg) — Drug and vaccine makers working on Covid-19 medicines rallied after President Donald Trump hinted at a “big surprise” coming soon, while day traders continued to favor a handful of smaller developers.Vaxart Inc., which also said it made a deal to scale up production of its experimental vaccine, was among the standouts, gaining as much as 57% on Thursday. Lesser-known drug developers working on medicines for Covid-19, like microcap NanoViricides Inc., jumped as much as 25%, while CytoDyn Inc. surged 33%.Sorrento Therapeutics Inc. climbed 30% before paring its gain. The stock shot up and appeared on investor radars in May after the chief executive and founder touted early data on Fox News.Some Wall Street analysts have suggested that Trump may try to push through a vaccine before the November election to score a win in the eyes of voters, spurring concerns about safety and effectiveness. With a recent surge in U.S. Covid-19 cases, day traders are looking for potential winners, and more skilled investors are having trouble catching up.“I think we’re coming up with some great answers,” Trump said in reference to Covid-19 vaccines and treatments on Wednesday afternoon. “I think you’re going to have a big surprise, a beautiful surprise sooner than anybody would think.”Day traders have been been jumping into some lesser-known small cap vaccine makers. Inovio Pharmaceuticals Inc. and Novavax Inc. were among the most popular trades in the past 24-hours, according to data from RobinTrack, which tracks Robinhood accounts holding shares. The pair are also the biggest winners on the Russell 2000 so far this year.Novavax rose as much as 11% on Thursday. The stock has surged more than 1,950% in 2020. Inovio shares jumped as much as 25%, though the gain moderated after short-seller Citron Research tweeted the stock would drop. Moderna Inc., one of the leaders in the efforts to develop a vaccine, reversed course after an Axios report suggested the company may not have full rights over its shot.Benchmark analysts rushed to catch up to Inovio’s stock price, which has increased seven-fold this year, and raised their price target to $36 from $28 Thursday on “assumed favorable” data from the earliest results of its vaccine trial expected in the next few days.The jump in new cases may mean a “lowering the bar for anticipated efficacy for COVID-19 vaccines,” Benchmark said. Neither Inovio nor Novavax have had a product reach the market, though Novavax is expected to file for regulatory approval of its experimental inoculation for the flu soon.The pair took a small breather earlier this month when they weren’t named among potential candidates for the Trump administration’s Operation Warp Speed, but Wall Street analysts held out some hope that they could be among the program’s finalists.For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2020 Bloomberg L.P.