It got beaten so badly because of some analyst's note saying that REGN's blockbuster eye drug Eylea has been replaced by cheaper rival drugs. First, it was only rumored to be "10%" of total patients, secondly, its rheumatoid arthritis drug "sarilumab" that is under development with Sanofi is showing promising signs and is now in phase 3. Overall, reaction is a little overblown IMO, we can expect a bounce from here.