(Bloomberg) -- Wall Street didn’t see this one coming but retail traders might have, as one tiny biotech saw its value sliced in half overnight on disappointing results for its only medicine in clinical testing.

Before new data on an experimental drug combination for skin cancer sent Idera Pharmaceuticals Inc. into a tailspin, every analyst tracked by Bloomberg recommended buying the stock. The average price target among the five brokers following the drug developer was $9, suggesting a roughly 70% return over Thursday’s closing price.

But after the drug missed a key goal in a late-stage trial, the company saw its shares plunge by as much as 65%, the biggest intraday drop in eight years. Every one of those analysts cut their rating in the past 24 hours, now recommending investors hold onto the stock. So far, none have recommended selling the Cambridge, Massachusetts-based drug maker.

In Idera retail trading, “the last couple months have seen persistent selling with the occasional pop higher,” Eric Liu, the co-founder of Vanda Research said in an email. Data from VandaTrack, a unit of Vanda Research, shows that retail traders cumulatively sold off about 79,000 shares in March, the heaviest selling happened on March 17, when over 106,000 shares were dumped by day traders.

In this case, Main Street may have been wiser than Wall Street and Idera’s top investors -- funds tied to the Beirut-based Pillar Invest Corp. and a hedge fund run by the billionaire health-care investor brothers Julian and Felix Baker. Today’s about face should sound an alarm for retail investors using their stimulus checks to dabble in penny stocks. For those chasing after quick returns, biotechs may be especially risky as the chances of successfully getting a new drug from the earliest stage of human testing to regulatory approval are about one in 10.

Meme stocks and tiny biotechs drove Nasdaq trading volumes on Friday as stocks like Clovis Oncology Inc., SuperCom Ltd, Senestech Inc and Hall of Fame Resort & Entertaiment Co. rallied.

©2021 Bloomberg L.P.