tasty trade POP
          (2015-08-06 16:00:50)
          下一個 
      
      
      
                  The	symmetry	of	Brownian	motton,	something	like	which	is	entailed	 by	an	efficient	market	hypothesis,	means	that	once	an	underlying	 reaches	a	price	point,	it	has	probability				of	being	above	or	below	 there	later.	Solving	this	with	algebra,	we		get	what	is	known	as	the	 reflec?on	principle:	the	probability	of	a	touch	is	twice	the	probability	 of	profit.	This	means	that	by	managing	winners	we	can	almost	 double	our	probability	of	profit.	Of	course,	that	would	require	taking	 winners	off	the	mo-	ment	they	made	a	penny	and	is	not	a	good	plan,	 but	it	shows	the	scale	on	which	managing	winners	can	supplement	 your	probability	of	profit.	Conversely,	aYempts	to	manage	losers	will	 hurt	your	probability	of	profit,	since	some	of	those	losers	you	closed	 out	were	going	to	turn	around
It	is	also	worth	noting	that	the	delta	of	a	naked	op?on	is	very	close	 to	it’s	probability	of	profit,	and	many	traders	use	it	as	a	proxy
pop = (width	of	the	strikes	–	credit	received) / width	of	the	strikes