Modern economic theory does not provide a sound foundation on which to build econophysics. Pivotal concepts like utility maximization, perfect competition, and diminishing marginal productivity are empirically and logically flawed. Physicists should not use any of these in econophysics, and...

In their path-finding 1973 paper, Black and Scholes presented two separate derivations of their famous option pricing partial differential equation. The second derivation was from the standpoint that was Black's original motivation, namely, the capital asset pricing model (CAPM). We show here,...

It has been recently noticed that time series of returns in stock markets are of multifractal (multiscaling) character. In that context, multifractality has been always evidenced by its statistical signature (i.e., the scaling exponents associated to a related variable). However, a direct...

The question of information cascades in finance appears in the literature. We use the dynamics of Kolmogorov's 1962 (K62) turbulence model, an example of multiaffine scaling, to illustrate how evidence for diffusion from large to small length scales, or correspondingly an information cascade...

This paper reports several entirely new results on financial market dynamics and option pricing. We observe that empirical distributions of returns are much better approximated by an exponential distribution than by a Gaussian. This exponential distribution of asset prices can be used to develop...

It has been repeatedly reported that time series of returns in stock markets are of multifractal (multiscaling) character. Recently, a direct geometrical framework, much more revealing about the underlying dynamics than usual statistical approaches, has been introduced. In this paper we use this...

We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies...

Extending previous work on non-equilibrium option pricing theory (Eur. Phys. J. 14 (2000) 383–394), a mean field approach is developed to understand the curvature of (implied by Black–Scholes (BS)) volatility surfaces (curves) as a function of moneyness (strike price divided by price). The...