Browsing Cherokee translation

5.

@FUNCTION=OPT_BS_THETA
@SYNTAX=OPT_BS_THETA(call_put_flag,spot,strike,time,rate,volatility[,cost_of_carry])
@DESCRIPTION=OPT_BS_THETA uses the Black-Scholes model to calculate the 'theta' of a European option with call_put_flag, @call_put_flag struck at @strike on an asset with spot price @spot.

(The theta of an option is the rate of change of its price with respect to time to expiry.)

@time is the time to maturity of the option expressed in years
and @rate is the risk-free interest rate to the exercise date, in percent.
@volatility is the annualized volatility, in percent, of the asset for the period through to the exercise date.
@cost_of_carry is the leakage in value of the underlying asset, for common stocks, this would be the dividend yield.
* The returned value will be expressed as minus the rate of change of option value, per 365.25 days.

@EXAMPLES=

@SEEALSO=OPT_BS, OPT_BS_DELTA, OPT_BS_RHO, OPT_BS_VEGA, OPT_BS_GAMMA