Alternative energy issue First Solar, Inc. (FSLR) attracted the attention of a skeptical options trader today. Not long after the opening bell, a skeptically skewed short call spread crossed the tape on FSLR, with the speculator betting on lackluster price action during the short term.

Around 10:35 a.m., a block of 236 April 120 calls traded near the ask price, suggesting they were purchased. Simultaneously, a matching block of 236 April 115 calls changed hands near the bid price, indicating they were most likely sold. With FSLR trading around $110 at last check, both of these options are out of the money.

Amgen Inc. (AMGN) announced this morning that its board of directors has authorized an additional stock buyback of up to $5 billion. The newly approved program adds to AMGN's existing share repurchase plan of roughly $1.2 billion. "This new authorization reflects Amgen's confidence in its long-term prospects," said the biotech firm in a press release.

Apparently, AMGN's confidence is not contagious, with the stock trading fractionally lower at last check. In fact, the stock is now hovering below short-term support from its 10-day moving average, which has been breached only once on a daily closing basis since early November.

For many investors, the strategies I covered in parts one and two of this series are more than enough options for their liking. But for some readers, the really return-hungry readers, they want more strategies -- more ways to utilize these derivatives. Unfortunately for those readers (and fortunately for the first category), this is my last options strategy piece.

This strategy is easily the most complex of the three I've discussed, but it also has its uses. This strategy -- credit spreads -- allows investors to sell options that aren't "covered" or "cash secured," but the risk is still very limited if done correctly. To tell you the truth, this is the most speculative of any of the strategies discussed in the series.

Essentially, a credit spread is created by selling an option and simultaneously buying a cheaper, further from strike option. The more expensive, closer in-the-money option is sold to collect the premium while the further out-of-the-money option is bought in order to limit the risk of the position. For example, if you sell 25 call options and buy 30 call options, the maximum risk is $500 per contract vs. unlimited if there is no purchased option. This strategy is pretty versatile because you can use it with puts or calls.

Like the other two "strategy sessions," I'll do my best to teach through examples.