What happened

Shares of Editas Medicine (EDIT -3.78%) were down 6.8% as of 3:51 p.m. EST on Thursday. The company didn't report any news that would cause its stock to fall. Instead, Editas' decline resulted from the overall stock market sell-off.

So what

Clinical-stage biotech stocks tend to be a lot more volatile than the major benchmark indexes. When the market drops, these stocks often fall even harder.

What should investors do? Sit tight. Market swings come and they go. The important thing to focus on is Editas' prospects for its gene-editing therapies in development.

Multiple DNA double helixes with a healthcare professional in the background

Image source: Getty Images.

The biotech has two clinical studies moving forward. Editas is dosing patients in its early-stage study evaluating EDIT-101 in treating rare genetic eye disease Leber congenital amaurosis type 10 (LCA10). It has also initiated a phase 1/2 study evaluating EDIT-301 in treating sickle cell disease.

Now what

The major milestone to watch for with Editas will be the initial results from its study of EDIT-101. The company expects to report those results later this year. Editas also hopes to file by the end of the year for U.S. Food and Drug Administration (FDA) approval to begin a study of EDIT-301 in treating rare blood disorder beta-thalassemia.