(Bloomberg) -- Two tiny biotechs, ISpecimen Inc. and Longeveron Inc., are the latest to see their stocks more than double in a social media-fueled frenzy ahead of a U.S. trading holiday. 

ISpecimen more than doubled in Tuesday’s premarket session and was up 95% at 9:28 a.m. More than 12 million shares traded hands before the bell, surprising for a stock with a float of less than 500,000 shares, according to data compiled by Bloomberg. The stock is majority held by individuals and about 44% of shares are held by insiders.

The gains in these select companies comes in the wake of a slide in the Nasdaq Biotech Index, which closed Monday at the lowest since June.

Daytraders are still chasing after electronic vehicle stocks like Rivian Automotive Inc. and Lucid Group Inc. as well as big tech names Nvidia Corp. and Apple Inc. On Monday, they added ISpecimen, which connects human samples with researchers, and Longeveron, a cell therapy company, to their watch lists and the stocks soared 80% and 181%, respectively. Both closed at the highest since their initial listings earlier this year.

The two biotechs joined diagnostic company Progenity Inc., as well as the EV and tech names, as the most-traded stocks on Fidelity’s platform on Monday. Longeveron and Progenity joined AMC Entertainment Holdings Inc. among the most-mentioned companies in Stocktwits over the past 24 hours.

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