Stocks limp into the close. Finish mixed. Read more.

Premium buyers are driving flow in Forest Oil options today, picking up several thousand near term out of the money calls and puts that ahead of earnings next week. Just before noon a sweep router was used to pay 35cents for 2000 May 15 puts, in a trade that appears to close some of the existing OI at the strike. Buyer also paid 15c for nearly 2000 May 20 calls near the same time, shown by ISE data to be opening customer.

Wendys/Arbys (WEN) Shares of Wendy ?s are breaking down some $0.45 or 9% to below $5.00 a share today. So this might not have been an opportune time for this morning ?s purchase of a chunk of the May $5 calls as 2,700 were swept up at the ask price of $0.40 contract. This drove IV up some 20 percentage points to a front month reading approaching the 100% level. It ?s possible this was closing as prior open interest in the strike was 4,420 contracts. But more bullish call buying ensued even as shares fell. Of note is the 1,000 contracts traded in the June $5 call at its $0.50 ask against prior open interest of 90 contracts. The company is slated to report earnings May 7. Unlike many restaurant chains, especially in the low cost space, Wendy ?s has not seen its share price increase in the past six weeks.

Visa (V) and Mastercard (MA) options are busy Thurday. Visa is up $1.88 to $65.39 and options volume is running 3X the usual after the co. reported quarterly earnings of 73 cents per share on $1.65 bln in revenues. Analysts were expecting 64 cents on $1.61 bln. Mastercard, which follows with earnings tomorrow (before market), is up $3.79 to $182 and hit 7-month highs today. Options volume is running 2X the usual, with May calls with strike prices from 180 to 220 seeing active trading. Implied volatility is up to 56 from 54 the day before.

The Powershares WilderHill Clean Energy Fund (PBW) holds shares in 51 companies that focus on greener and renewable energy sources. (Link to product specs). PBW includes some of today’s hot solar names, including First Solar (FSLR), Evergreen Solar, and JA Solar (JASO), and is up 34 cents to $9.08. (Link to story). In the options, volume is running 11X the usual, with June 10 puts leading the flow. The top trade is 716 contracts for $1.30 on the ISE, which is an opening customer buy according to sentiment data. 100 percent of the 2000 contracts traded hit ask-side.

Potash (POT) is up $1.17 to $86.76 and January 2010 puts at the $55 strike are seeing increasing interest. More than 12.7K traded, compared to open interest of 1,364. Today’s actvity includes several large blocks hitting at the offer for between $4.30 and $4.50 on the PHLX. Looks like premium buyers opening new positions–some possibly tied to shares. The Ag/Chem ETF (MOO) moved to 6-month highs earlier and is testing the upper end of its recent range. Briefing mentions takeover chatter on POT today.

First Solar Boosts the Solar Index. Read More.

Arena (ARNA) is up 27 cents to $2.78 and the October 2.5 put – 4 call strangle is seeing interest. Today’s 5200 includes a purchase for $1.80 and tied to 170K ARNA shares at $3 even. In other words, the strategist bought the shares, bought 2.5 puts and bought bought 4 calls, which is a position that will generate better profits if ARNA moves substantially higher, not lower.

Wellcare Healtch (WCG) is up 50 cents to $14.95 and 2100 calls traded on the managed healthcare company, compared to just 55 puts. Today’s call volume represents 7.5X (757 percent) the expected for this time of day. May 17.5 calls are the most actives. The increased volume seems to include a mix of buyers and sellers and comes amid renewed takeover chatter–Briefing.

Also known as the Exercise Price, the strike price is the price at which a call buyer can call the underlying asset or a put buyer can sell the underlying security. When assigned on an options contract, the put writer must pay the strike price and the call writer must accept the exercise price. Each option contract has a specific strike price, which is exremely valuable in determining the market value of that put or call option.