As you’re probably aware, a number of market systems exist that claim to be sure money makers. That shouldn’t be surprising given the number of market traders expending time and effort on developing systems to capitalize on trends and anomalies within the market. But not all these systems are as reliable as they claim to be. Smart traders will choose carefully, or watch their hard-earned capital drain away.

One system that can be effective when practiced correctly is theta decay. Don’t be intimidated by the fancy name; the underlying concept is actually quite simple. The system is based on a fact that all option traders know: options expire on a specific, known, date.

Because option trading instruments have a finite life span, their value would tend to change as they come closer to the strike date. In analyzing trends in trading of options, the spread of prices that exist between the issuance date and the strike date is shown to get smaller as the issue nears expiration.

Theta decay analysis is able to serve as the basis for an option trading system because, compared with stocks, options are much more information-rich. The existence of an expiration date gives options traders the information foothold they need. Big gains can result for those able to keep up with the brisk flow of options information.

Actually, it’s not that difficult to use theta decay techniques to cash in on those gains. Remember the fundamental concept: the closer the expiration date is, the faster the time value changes. In particular, studies show that the time value of an option decreases according to a linear trend until approximately the last thirty trading days prior to expiry.

Those last thirty days are where this set of option trading strategies comes into full effect. As the issue gets closer within that thirty day period, the time value of the option starts to decline at an accelerated rate. As a result, if you hold certain positions, you can profit from this loss.

Imagine, for example, that you have an option approaching expiration and hold a short position while also selling an inverse call option. You could realize two separate gains. The first of these comes when you sell the call at a premium relative to its actual value. The second can result if the option does not finish on the positive side in money.

Ultimately, with good timing and keen senses for information gathering, you can use theta decay as part of your stock option trading strategy. Of course, there is always the risk of losing your principal if you’re not careful, but if you can read the market well and pay attention to expiration dates of options, you too could make money from this not so well known but obvious market strategy.