Mallinckrodt Spikes On Citron Tweet

Mallinckrodt PLC MNK is up 5.56 percent at $54.80 on Friday.

Possibly contributing to the spike is a tweet from Citron Research, which read: "@CitronResearch Clarification: Citron does not recommend short $MNK at $54 for short-term. Wait for fundamentals to ‘kick in' and guide lower –like $VRX."

This is not the first time the stock has moved on Citron news.

Earlier in the week, Citron's Andrew Left issued a note to clients regarding Mallinckrodt and Valeant Pharmaceuticals Intl Inc VRX.

Related Link: Citron: Mallinckrodt Makes Valeant Look Like Choirboys

In the note, Left called Mallinckrodt the "poster child" for price gouging. Subsequently, Valeant plunged 50 percent and Mallinckrodt fell subject to a related selloff.

Valeant is currently down 9.33 percent at $26.92.