2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148660We show, by studying in detail the market prices of options on liquid markets, that the market has empirically corrected the simple, but inadequate Black-Scholes formula to account for two important statistical features of asset fluctuations: `fat tails' and correlations in the scale of fluctuations. These aspects, although not included in the pricing models, are very precisely reflected in the price fixed by the market as a whole. Financial markets thus behave as rather efficient adaptive systems.Revised version, 1 figure addedCondensed Mattertext