That was one of the initial reasons I raised the questions earlier in this thread (review it). In addition to delta> 0.5, saying ATMF delta is equal to 0.5 is equivalent to saying price of option is zero. A price of an ATMF call option is positive (nonnegative) is equivalent to saying its delta is positive (nonnegative). I am not familiar with Derman and his/her work. How did he/she prove that delta is >0.5? It would be useful to reproduce his/er arguments/proofs here. Others gave other good insights (review thread).
Well I don't know, "I think I got intellectual rights on it..." Here it is. That is ATMF, C/S=sqrt(sigma²T/(2*3.14159)) MasterAtWork
I'm still waiting for yours... Don't forget you got an option pricing scheme without a model that would match market prices to show us.
1. "?" was a question, which meant I did not understand what your question was from what you wrote. 2. Behind smoke there is always fire. You disagree?
I like the analogies. Thanks. Water is a source/sign of life, and innate cash borrows from it its liquid attribute. Even in its solid dry form, it makes a man enjoy the drinks that his cash can buy. So, the smoke may lead to something useful after all-- no blames if one were to want to find out what is exactly behind it. Option theory teaches that rational people should not write call options for free-- Are you asking that people commit a "major" options sin?
Smoking crystal meth and watching computer porn makes you eligible to receive tickets to sports events, lunches, hunting/fishing trips and other gifts from energy companies. Work for the Minerals Management Service (MMS)!