%0 Journal Article %T Can there be an explicit formula for implied volatility? %A Stefan Gerhold %J Quantitative Finance %D 2012 %I arXiv %X It is "well known" that there is no explicit expression for the Black-Scholes implied volatility. We prove that, as a function of underlying, strike, and call price, implied volatility does not belong to the class of D-finite functions. This does not rule out all explicit expressions, but shows that implied volatility does not belong to a certain large class, which contains many elementary functions and classical special functions. %U http://arxiv.org/abs/1211.4978v1