Idenix Pharmarceuticals (IDIX) adds $2.80 to $9.85 on positive trial results from a Hepititis C drug and one player seized the strength to write 10,000 Jan $10 calls on the biotech for an average of 52.5 cents per contract to open. 12,618 now traded against 278 in open interest. Meanwhile, implied volatility in options on IDIX is up another 20 percent to 137, even as this company event-risk has passed. Briefing notes today that IDIX and peer ACHN have both been considered M&A candidates and another name in the space — INHX — was taken out at a hefty premium by BMY over the weekend.

*Scanning all single-stocks subject to 2500 contracts minimum call or put volume

Safeway (SWY) adds 41 cents to $21.64 and a multi-exchange sweep of 5,000 Feb 20 puts on the stock for 30 cents per contract is an opening customer buyer, according to data from the ISE. 5,420 traded against 142 in open interest. Implied volatility in SWY options is up 8.5 percent to 25, as some investors might be looking to hedge recent gains in the underlying. The stock is up 34.6 percent since 9/23. Earnings due around Feb 23 and possibly outside the February expiration.

*Scanning all single-stocks subject to 2500 contracts minimum call or put volume

General Motors (GM) adds 24 cents to $23.16 and a Jan – Feb 20 call spread is bought on the automaker for 25 cents, 12500X, and probably rolls a bullish position in in-the-money calls out an additional month. After losing 45 percent in 2011, GM has performed well lately. The stock is on a seven-day 16.9 percent winning streak, with help from December sales results Wednesday and an S&P credit rating upgrade Thursday.