Otix Global shares rallied after William Demant Holding said it will buy the hearing care company for $8.60 per share in a $50 million deal. Separately, Otix Global said it will discontinue its German operations on Tuesday, adding that regulatory obstacles in Germany "have dramatically impacted the feasibility of stability of our business." Shares of Otix Global surged by $4.31, or 106.7%, to $8.35. Volume topped 2.38 million shares, compared to the average daily share volume of only 12,000. Elsewhere, Entropic Communications ( ENTR) jumped by 59 cents, or 6.9%, to $9.19 after the semiconductor company raised its third-quarter guidance. Entropic now expects third quarter revenue to range between $60 million and $61 million, up from its previous range of $51 million to $53 million. Volume topped 4.22 million shares, compared to the average daily share volume of 1.85 million. Opexa Therapeutics ( OPXA) rallied by 69 cents, or 62.7%, to $1.79 after the biopharmaceutical company ahead of a presentation Tuesday at the Rodman & Renshaw Annual Healthcare Conference. Opexa's presentation, which will focus on the company's Tovaxin lead therapy for multiple sclerosis, will begin at 4:30 p.m. ET. Volume on Monday topped 1.67 million shares, compared to the average daily share volume of 65,000. -- Written by Robert Holmes in Boston. >To contact the writer of this article, click here: Robert Holmes. >To follow Robert Holmes on Twitter, go to http://twitter.com/RobTheStreet. >To submit a news tip, send an email to: email@example.com.