Buzz Stocks: Twitter Inc, Dynavax Technologies Corporation, and Corbus Pharmaceuticals Holdings Inc

U.S. stocks are mostly higher after a monster week, though tech stocks continue to underperform. Among specific equities in focus today are social media concern Twitter Inc (NYSE:TWTR), as well as biotech stocks Dynavax Technologies Corporation (NASDAQ:DVAX) and Corbus Pharmaceuticals Holdings Inc (NASDAQ:CRBP). Here's a quick look at what's driving TWTR, DVAX, and CRBP.

• TWTR is up 2% at $18.92, after Jana Partners LLC announced it had taken a 2.9 million-share stake in the social media company. TWTR is still down 25% since its early October peak of $25.25, gapping lower as buyout hopes dissipated, and now sits under the $19-$20 region, which has acted as resistance at several points since the beginning of the year. A few option bulls are likely cheering today's vote of confidence from Jana, with Twitter Inc's 10-day call/put volume ratio at the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) of 4.52 sitting in the top 10% of TWTR's annual range.
  
  
• DVAX is trading down 65.1% at $4.04, and has landed itself on the short-sale restricted (SSR) list, on news the U.S. Food and Drug Administration (FDA) has rejected its hepatitis B vaccine for the second time, citing "adverse events" during clinical trials. Dynavax Technologies Corporation shares now sit 84% lower for 2016, earlier touching a seven-year low of $3.20. Even on the SSR list, a number of short sellers are likely cheering today's development, with DVAX's short interest up by nearly 25% over the last two reporting periods. Shorted shares now account for more than one-third of DVAX's float, which would take nearly three weeks of trading to cover, at DVAX's average daily volume.

• CRBP is 69.7% higher at $9.92, following positive Phase II trial results for its systemic connective tissue disease treatment, Resunab. CRBP now sits up a whopping 500% since the beginning of 2016, though it's still shy of its record high of $10.78, touched in October. While option buyers have been more optimistic than usual lately -- CRBP's 50-day call/put volume ratio at the ISE/CBOE/PHLX shows nearly 2.3 calls bought to open for every put over the last 50 days of trading -- today's Resunab news defies at least one firm's rock-bottom expectations.

Stay on top of overnight news & big morning movers. Sign up now for Schaeffer's Opening View.