The Value of any option is based on three main variables
1) INTRINSIC....The REAL value of the option based
on the relationship between the stock price and the strike price. Eg if the stock is at 25c and the option is at 20c strike
there is a REAL or intrinsic value of 5c because we can exercise the option, buy shares at 20c, then sell them in the market
at 25c. If the stock is at 10c the option has no REAL or intrinsic value it only has some value based on HOPE.
2) TIME....The longer the option has to run the more
HOPE you have so the hope value of an option is higher for an option with a longer time to expiry.
3) VOLATILITY.....There is a higher probability that
stock that has big swings will move up and trade at a given target than a stock that is very quiet and does nothing. So the
HOPE value of an option is higher for volatile stocks. Eg NCP which trades all over the place has a volatility of 40% so the
options are much more expensive than TLS whose volatility is around 16%.
The theoretical value of an option is calculated using
quite a complex equation the Black Scholes formula using these 3 main inputs and the interest ratewhich is the fourth variable.Dividends
payable are also included in the clculation.....sorry you can't make a quick buck by buying a put the day before a stock
goes ex dividend.
DO YOU REALLY WANT TO SEE THE FORMULA?
GREEKS...What happens to the option if the variables change
Delta: the degree to which an option price will move given a small change in the
underlying stock price. For example, an option with a delta of 0.5 will move half a cent for every full cent movement in the
underlying stock.
Or..Bang for your bucks...how zippy it is....
Gamma: It measures how fast the delta changes for small changes in the underlying
stock price. ie the delta of the delta.
Vega: The change in option price given a one percentage point change in volatility.