We propose a new non parametric technique to estimate the CALL function based
on the superhedging principle. Our approach does not require absence of
arbitrage and easily accommodates bid/ask spreads and other market
imperfections. We prove some optimal statistical properties of our estimates.
As an application we first test the methodology on a simulated sample of option
prices and then on the S\&P 500 index options.Comment: arXiv admin note: text overlap with arXiv:1406.041