by John Summa (
Contact Author |
Biography)
Greeks play a critical role in strategy behavior, most importantly in determining the prospects for success or failure. The key Greek risk factors -
Delta,
Vega, and
Theta - were explained both in terms of how each relates to options in general (i.e., What is the sign on the
Delta of all call or put options, or what is sign on the
Theta of a call or put option?). While
Deltas of calls are always positive and
Delta of puts always negative, for the other Greeks the signs for puts and calls are the same.
Theta is negative for all options because whether puts or calls, each tick of the clock reduces premium on an option, other things remaining the same. Likewise, all options have positive
Vega values, since regardless of whether call or put, a rise in volatility will add value, while a decline will take value away. When moving to the level of position Greeks (i.e., Which strategy is employed and which strategy Greeks are associated with it?), the picture gets more complicated.
Calls and puts can have either negative or positive Greeks depending on whether or not they are short (sold) or long (purchased). And a combination of options (calls and puts or different strikes using calls or puts) will result in a position
Delta,
Vega or
Theta depending on the net position Greeks in the strategy.
Finally, in the last part of this tutorial, the
ceteris paribus assumption (all things remaining the same) is dropped to look at how Greeks change when other things don’t remain the same, such as
implied volatility (IV) and time remaining to expiration. While just one avenue for exploration, it was shown how
Delta changes with both changes in time remaining until expiration and falling levels of IV. Further simulations along these lines could have been carried out, but due to the limitation of space it is not possible here.
Suffice it to say that a rise in implied volatility will have the reverse impact in similar magnitudes for calls and puts. As for other scenarios, it would be best to acquire some software or access to a sophisticated broker platform that allows for extending this type of multidimensional analysis to other strategies.
For now, bear in mind that each strategy will be impacted by changing levels of implied volatility (which can hurt or help depending on the sign and size of the position
Vega), time remaining to expiration (position
Theta risk), and to a smaller extent interest rates (typically negligible for most short- to medium-term strategies).
With enough practice, eventually an understanding of the relationships of the Greeks to each strategy will become second nature so that analysis only becomes necessary to calculate their exact magnitude if using large lot sizes.
Remember, it is better to trade smart. Begin slowly, risking little, and eventually increase risk when you begin to achieve success on small positions.
by
John Summa, Ph.D., is the founder and president of
OptionsNerd.com LLC. He co-authored "
Options on Futures: New Trading Strategies and Options on Futures Workbook" (2001). He is also the author of "
Trading Against The Crowd: Profiting From Fear and Greed in Stock, Futures and Options Markets" (2004), which presents contrarian sentiment trading indicators and trading systems for stocks, futures and options.
Founded in 1998, OptionsNerd.com provides professional training and educational support to stock, options and futures traders. Summa is an economist, author, options trader and former professional skier, and he presents small-group, online and in-person training seminars.
