Focus Universal (FCUV) shares were down 51% in premarket activity Tuesday after the company announced the exercise of warrants to buy common shares at $13.32 apiece, raising about $3.7 million in gross proceeds.

Dyne Therapeutics (DYN) stock was down 25% after a 2.7% decline in the prior trading day.

Sigma Lithium (SGML) shares were 16% lower following a 3% fall at the prior close. The company said Monday that its mining and industrial operations remain unaffected by a preliminary judicial ruling that allegedly suspends its environmental licenses.

Laser Photonics (LASE) stock was down 15% following the Friday US Securities and Exchange Commission filing that included the announcement of an offering of up to roughly 7.1 million common shares.

Baosheng Media Group (BAOS) shares were 10% lower, swinging from the 16% rise in the previous session.