Crude Crushes Early Dow Jones Industrial Average Gains

After jumping to a triple-digit lead, the Dow Jones Industrial Average (DJIA) has pared its early gains -- and briefly turned negative -- as a dismal first week of the year approaches an end. Chinese stocks traded higher today with the circuit-breaker mechanism suspended, and a strong jobs report also sparked early upward momentum. However, oil is taking the wind out of the bulls' sails, as crude once again explores decade-plus lows.

Continue reading for more on today's market -- and don't miss:

• 2 battered biotechs attempting big rebounds.
• Qorvo Inc (NASDAQ:QRVO) and this fellow Apple supplier are curbing current-quarter enthusiasm.
• Plus ... Checking in on the CBOE Volatility Index (VIX), the SPDR S&P 500 ETF Trust (SPY), and other noteworthy stats at midday.

Among stocks with unusual option volume today is Activision Blizzard, Inc. (NASDAQ:ATVI), where calls are crossing the tape at four times their typical intraday rate, and outnumbering puts more than 20-to-1. The resulting put/call volume ratio of 0.04 is lower than 99% of readings over the past year. Most of this action appears to be sell-to-open activity at the January 2016 37.50 strike, however -- indicating that option traders aren't expecting ATVI to see significant upside in the near future. The shares are down 1.2% at $35.83 today, but should find support atop their 80-day moving average.

Silicone implants producer Sientra Inc (NASDAQ:SIEN) is among the top performers on the Nasdaq today, surging 9% to $6.43, after an independent test affirmed that its products are safe for patients. SIEN fell off a cliff in late September, when U.K. regulators questioned its implants and suspended certification for some products, but the stock has picked up steam since hitting a record low of $2.77 in mid-November. There are lots of bears likely kicking rocks today. Short interest on the equity more than doubled over the last two reporting periods.

Barracuda Networks Inc (NYSE:CUDA) is among the worst stocks on the Big Board at midday, dropping 33% to $11.00 -- and tapping a new all-time low of $10.52 -- after reporting disappointing quarterly earnings. Traders should hardly be surprised -- CUDA has fallen hard after financial reports twice in the last six months.

The CBOE Volatility Index (VIX) is down 0.7 points, or 2.7%, at 24.32.

Today's put/call volume ratio on the SPDR S&P 500 ETF Trust (SPY) is 1.34, with puts outnumbering calls. SPY was last seen up 0.3 points, or 0.2%, at $194.31.