Editing Put–call parity (section)

==Implications==
Put–call parity implies:

* ''Equivalence of calls and puts'': Parity implies that a call and a put can be used interchangeably in any [[delta neutral|delta-neutral]] portfolio. If <math>d</math> is the call's delta, then buying a call, and selling <math>d</math> shares of stock, is the same as selling a put at the same strike and selling <math>1 - d</math> shares of stock. Equivalence of calls and puts is very important when trading options.{{cn|date=July 2017}}
* ''Parity of implied [[volatility (finance)|volatility]]'': In the absence of dividends or other costs of carry (such as when a stock is difficult to borrow or sell short), the [[implied volatility]] of calls and puts must be identical.<ref name="JHull">{{cite book | last = Hull | first = John C. | edition = 5th | title = Options, Futures and Other Derivatives | year = 2002 | publisher = [[Prentice Hall]] | pages = [https://archive.org/details/optionsfuturesot00hull_1/page/330 330–331] | isbn = 0-13-009056-5 | url-access = registration | url = https://archive.org/details/optionsfuturesot00hull_1/page/330 }}</ref>