News Focus
News Focus
Followers 21
Posts 6692
Boards Moderated 1
Alias Born 07/09/2009

Re: **D*A** post# 100301

Wednesday, 06/06/2012 2:46:57 PM

Wednesday, June 06, 2012 2:46:57 PM

Post# of 126122
EDIT i'm tapped out for my posts today bro, ttyl. that also is pretty much what i try to do, then i look at the iv b4 jumping in to make sure its not up 400 percent or somthing lol. but we're getting better and better.

yup sounds about right.. for the most part this is the greek you keep an eye on when figuring out loss as far as time goes.

Theta


Theta, a.k.a. time decay, is an estimate of how much the theoretical value of an option decreases when 1 day passes and there is no move in either the stock price or volatility. Theta is used to estimate how much an option's extrinsic value is whittled away by the always-constant passage of time. The theta for a call and put at the same strike price and the same expiration month are not equal. Without going into detail, the difference in theta between calls and puts depends on the cost of carry for the underlying stock. When the cost of carry for the stock is positive (i.e. dividend yield is less than the interest rate) theta for the call is higher than the put. When the cost of carry for the stock is negative (i.e. dividend yield is greater than the interest rate) theta for the call is lower than the put.
Long calls and long puts always have negative theta. Short calls and short puts always have positive theta. Stock has zero theta – its value is not eroded by time. All other things being equal, an option with more days to expiration will have more extrinsic value than an option with fewer days to expiration. The difference between the extrinsic value of the option with more days to expiration and the option with fewer days to expiration is due to theta. Therefore, it makes sense that long options have negative theta and short options have positive theta. If options are continuously losing their extrinsic value, a long option position will lose money because of theta, while a short option position will make money because of theta.
But theta doesn't reduce an option's value in an even rate. Theta has much more impact on an option with fewer days to expiration than an option with more days to expiration. For example, the XYZ Oct 75 put is worth $3.00, has 20 days until expiration and has a theta of -.15. The XYZ Dec 75 put is worth $4.75, has 80 days until expiration and has a theta of -.03. If one day passes, and the price of XYZ stock doesn't change, and there is no change in the implied volatility of either option, the value of the XYZ Oct 75 put will drop by $0.15 to $2.85, and the value of the XYZ Dec 75 put will drop by $0.03 to $4.72.
Theta is highest for ATM options, and is progressively lower as options are ITM and OTM. This makes sense because ATM options have the highest extrinsic value, so they have more extrinsic value to lose over time than an ITM or OTM option. The theta of options is higher when either volatility is lower or there are fewer days to expiration. If you think about gamma in relation to theta, a position of long options that has the highest positive gamma also has the highest negative theta. There is a trade-off between gamma and theta. Think of long gamma as the stuff that provides the power to a position to make money if the stock price starts to move big (think of a long straddle). But theta is the price you pay for all that power. The longer the stock price does not move big, the more theta will hurt your position.
Position theta measures how much the value of a position changes when one day passes. Position theta is calculated much in the same way as position delta, but instead of using the number of shares of stock per option contract, theta uses the dollar value of 1 point for the option contract. (The dollar value of 1 point in an option contract for U.S. equities is usually $100, but can be different due to stock splits.) thinkorswim takes the theta of each option in your position, multiplies it by the number of contracts and the value of 1 point for the option contract, then adds them together.


info on the other greeks check this out
https://www.thinkorswim.com/tos/displayPage.tos?webpage=lessonGreeks


all posts are theoretical concepts and idea's designed to promote educated discussion and should not be considered advice to buy or sell securities.

Discover What Traders Are Watching

Explore small cap ideas before they hit the headlines.

Join Today